


aV <r> 



- \ 






/ 










,♦ 






^' ^"'^^^^.c 










,v 



r% ^.mw.- <^ ^. 



^t"^ 



■:> is ^ <.^ .10 '^ ^ O i> X 






^ 



$^% 



^ 



H ^^ 






V I ft 



'i- *}■ 




Ci> 







•>,. 



9 I 



V o 



c 



^\ 



.^ 



s> 







,0o. 



\ * r 




^' ^^ 



fciv^%-" 



\ ^ 





Cv 



/ . . s '^ <0 






^ 



^ 







'\ 



O. ^/ 




-0- 



'VL 








%<' 



.- ^ 



'> N 



^/ 



\ 



\.'.^' 



^^ 








A v< 








« V -^ /\ 



C^"^ ^>? 



.0 o 





- A^ ^ <Ji c:> -^i *<> 






^^ 



V 






d^ 



V' </> 



L^^ ^^. 




,,#' -"^"^ 











.0^ 



,\ 



V V 







<. 



•f 







Digitized by the Internet Archive 
in 2011 with funding from 
The Library of Congress 



http://www.archive.org/details/elementsoflogick03hedg 



b- 




"y-y-A^S^ 



^l^'T^tt^'^ 







^ 



ELEMENTS 



OF 



logick; 



OR 



A SUMMARY OF THE GENERAL PRINCIPLES 



AND DIFFERENT MODES 



OP 



REASONING. 



BY LEVI HEDGE, a. m. 

PROFESSOR OF LOGICK AND METAPHYSICK5, IN 
HARVARD COLLEGE. 






r 






TUIRB EDITION. 



BOSTON : 




PUBLISHED BY CUMMINGS AND HILLIAKD, 



Univ, Fress..,..Hilliard & Metcalf. 

1821 






DISTRICT OF MASSACHtrSETTS TO WIT s 

/district Cleric's Office, 
BE IT REMEMBERED, that on the twenty Dinth day of May, A. D. 
1816, and in the fortieth year of the Independence of the United States of 
America, Levi Hed^e, Esq. of the said district has deposited in this office the 
title of a book, the ri^ht whereof he ciaims as author, in the words foi lowing-, vizu 
** Elements of Logick ; or a summary of the general principles and different 
modes of reasoning. By Levi Hedge, A. M Professor of Logick and Metaphys- 
icks, in Harvard College." 

In conformity to the Act of the Congress of the United States, entitled, " An 
act lor the < ncouragement of learning, by securing th^' copies of maps, charts, 
and books, to theviuthors and proprietors of such copies, during the times there- 
in mentioned ;" and also to an act, entitled, " An act supplementary to an act, 
entitled. An act for the encouragement of learning, by securing the copies of 
maps, charts, and books, to the authors and proprietors of such copies during 
the times therein mentioned ; and extending the oenefits thereof to the arts of 
designing, engraving and etching historical and other prints." 

* W. S. SHAW, 

Ckrk of the District of Massachusetts, 



<K 



PREFACE. 

Most of the treatises of Logick in common use have 
been formed on the model of the ancient sjstemj^, and 
are incumbejed with many scholastick subtilties and 
unimportant distinctions. The instructions, which they 
furnish on the subject of ratiocination, consist of very 
little more, than a description of the syllogism, and a 
few general principles of demonstrative reasoning. 
They contain no elements nor rules to assist us in 
reasoning on subjects of probability, or on the ordinary 
events of human life. The manner, in which these books 
are wiitten, is ill adapted to the comprehension of young 
minds. In explaining the operations of reasoning, many 
technical terms and arbitrary forms are employed, of 
which the tendency is rather to embarrass and perplex, 
than to instruct the learner. 

Though much has been written, of late years, on the 
powers and operations of the mind, yet there have been 
but few attempts to form a system of Logick for the U::^e 
of those, who are commencing the study. Collard has 
improved the syllogisn>, by symplifying its principles, 
and divesting it of its ancient trappings of modes and 
figures. Condillac has proved the importance of the 
method of induction, by pointing out the manner, in 
which nature teaches us to analyse the objects, which 



IV* PREFACE*:^ 

she presents to our observation. In ^' An Essay on the 
*' elements, principles, and different modes of reasoning,'* 
by Richard Kirwan, LL. D. all the subjects, which 
properly fall within the precincts of Logick, are amply 
discussed. But this work is too minute and prolix to he 
used as a text book in seminaries of education. Every 
person, who is much conversant with this department of 
knowledge, must have perceived the want of a treatise of 
Logick, more elementaiy., and better accommodated to 
the present improved state of thephilosophy of the mind, 
than any of those, which are now in use. 

The professed object of Logick is to furnish rules for 
the direction of the understanding in its various inqui- 
ries after knowledge. It should therefore teach the prin- 
ciples of every species of reasoning, which we have oc- 
casion to make use of, both in the pursuits of science, 
and in the ordinary transactions of life. Demonstrative 
reasoning can be employed only about general truths^ 
and such relations, as are in their nature immutable. 
It is of little use in regulating our judgments and con- 
clusions concerning events, which are irregular in their 
occurrence, and which depend on contingent circum- 
stances. To reason on subjects of this kind, it is ne- 
cessary to understand the nature of moral evidence, and 
the grounds of probability. It is by moral evidence 
alone, that we reason on historical facts, and the casual 
occurrences of life. It is also this evidence, which influ- 
ences our conclusions on the important and interesting 
subjects of government, morals, and religion. 

Under these impressions, the writer of this compend 



has pursued the following plan. After passing through 
the customary distinctions of terms and propositions, 
he has given a brief account of moral evidence, and 
pointed out the circumstances, which distinguish it from 
demonstrative. A concise view is then given of the dif- 
ferent forms of reasoning, with the principles, on which 
they respectively proceed. 

The books, which have been principally consulted in 
forming this summary, and in which the greatest part 
of the following principles may be found, are Watts' 
Logick, Lockers Essay on the Understanding, Reid's 
Essays on the Intellectual Powers, Stewart's Elements 
of the Philosophy of the Mind, Beattie's Essay on Truth, 
Tatham's Chart and Scale of Truth, Collard's Essentials 
of Logick, Kirwan's Logick, Campbell's Philosophy of 
Rhetorick, Gambier*s Introduction to Moral Evidence, 
Belsham's Compendium of Logick, and Scott's Elements 
of Intellectual Philosophy. 

Where passages have been borrowed entire, credit 
is given in the usual way. At the close of the several 
chapters may be found the names of those authors, from 

whom particular assistance has been derived. 

1^ 



PREFACE 

TO THE THIRD EDITION. 

The present edition of the Elements of 
Logick is printed in a smaller type^ than either 
of the preceding^ in order that the copies 
may be afforded at a reduced price. The 
author has carefully revised the work^ and 
has enlarged it by the addition of a few pages, 
containing some general principles and rules, 
respecting controversy, and also a system of 
rules for the interpretation of written docu- 
ments. These have been collected with care 
from authors of high reputation, and, it is hop- 
ed, will not be thought an unsuitable appendage 
to a system of logick. In a few places, slight 
alterations have been made in the language and 
in the arrangement ; and some notes have been 
inserted at the end of the book, which were not 
in the preceding editions. 

Harvard College, JVov* 1821. 



CONTENTS. 



PART FIRST. 



A DESCRIPTION OF THE LEADING FACULTIES AND OPE« 

RATIONS OF THE MIND. 



Introduction. - . - - - 

CHAP. I. 
Perception and Consciousness. 

CHAP. II. 
Attention. - - - - - - 

CHAP. IIL 
Comparing. - - - - - 

CHAP. IV. 
Abstraction. - - 

CHAP. V. 
Association. - - . - - 

CHAP. VI. 

Analysis, - - - - - - 

PART SECOND. 

OF TERMS AND PROPOSHTONS. 

CHAP. 1. 

Logical distinctions of lerms. 



Page. 
13 

15 

19 

21 
- 2S 

. £5 
£8 



SI 



X CONTENTS. 

CHAP. IL 
Definition and Division. - - - - 59 

CHAP. III. 
General description of Propositions. *• - 44 

CHAP, IV. 
Simple, Complex, and Modal Propositions. - 47 

CHAP. V. 
Quality and Quantity of Propositions. - - 50 

CHAP. VI, 
Opposition and Conversion of Propositions. - 55 

CHAP. VII. 
Compound Propositions. - - - - 59 

PART THIRD. 

OF JUDGMENT AND REASONING. 

CHAP. I. 

Intuitive Evidence. - - - - - 65 

CHAP. [T. 
Difference between Moral and Demonstrative Rea- 
soning, ----.---fO 

CHAP. HI. 
Induction. - • - - • - . 75 

CHAP. IV. 
Analogy ... - . . . 83 

CHAP. V. 
Reasoning on Facts. - - ... 88 

CHAP. VI. 
Calculation of Chances. - . - - 101 



CONTENTS, XI 

CHAP. VIT. 

I General description of Demonstrative Reasoning, 108 

CHAP. VKL 
Distinctions of Reasoning. . . - • us 

CHAR IX. 
General description of Syllogistick Reasoning. 116 

CHAP. X. 
Of Regular {Syllogisms. - . » - ^ 120 

CHAP. XL 
Enthymemes. ------ 130 

CHAP. xn. 

Conditional and Disjuntive Syllogisms. - - 134 

CHAP. xni. 

Compound Syllogisms. ----- 1S;7 

CHAP. XIV. 

Sophisms. - - - - « - - 144 

CHAP. XV. 

Disposition or Method. - - - ^ - 149 

Rules of Controversy. - - - - 157 

Rules of Interpretation. - • . . 162 

Concluding Remarks. - • - ^ - 167 

Notes and Illustrations. - - - - in 



ii^ 



ELEMENTS OF LOGICK, 



PART FIRST. 

A DESCRIPTION OF THE LEADING FACULTIES AND OPE 

llATIONS OF THE MIND, 



INTRODUCTION. 

1. The purpose of Logick is to direct the 
intellectual powers in the investigation of triithp 
and in the communication of it to others. Its 
foundation is laid in the philosophy of the hu- 
man mind^ inasmuch as it explains many of 
its powers and operations^ and traces the pro- 
gress of knowledge from the first and most sim- 
ple perceptions of outward objects^ to those 
remoter truths and discoveries^ which result 
from the operations of reasoning, 

2. Logick instructs us in the right use of 
termsj and distinguishes their various kinds. 
It teaches the nature and varieties of propo- 
sitions ; explains their properties^ modifica- 

2 



14 INTRODUCTION. 

tions^ and essential parts. It analyzes the 
structure of arguments^ and shows how their 
truth may be discovered^ or their fallacy de- 
tected. Lastly it describes those methods of 
classification and arrangement^ which will best 
enable us to retain and apply the knowledge^ 
which we have acquired. 

3. Though the understanding would be inca- 
pable of any high degree of improvement^ with- 
out the aid of rules and principles^ yet these 
are insufficient without practice and experi- 
ence. The powers of the mind^ like those of 
the body^ must be strengthened by use. 
The art of reasoning skilfully can be acquired 
only by a long and careful exercise of the 
reasoning faculty^ on different subjects and in 
various ways. The rules of logick afford 
assistance to this faculty^ not less important 
than that^ which our animal strength derives 
from the aid of mechanical powers and en- 
gines. They guide its operations^ and supply 
it with suitable instruments for overcoming the 
difficulties^ by which it would be impeded in 
its search after truth. 

4. In the following compend^ the subjects 
of logick are distributed into three parts. The 



PERCEPTION AND CONSCIOUSNESS. 15 

first contains a brief description of the lead- 
ing faculties and operations of the mind. The 
second;, of the several kinds of terms and prop- 
ositions. The third comprises an explana- 
tion of moral and demonstrative evidence ; 
of the diiferent modes of reasoning ; of soph- 
isms ; and of method^ or disposition. 

CHAPTER FIRST. 

PEllCEPTION AND CONSCIOUSNESS. 

5. Perception is the first faculty^ which ap- 
pears in the human mind. By this we gain all 
our knowledge of the powers and qualities of 
the material objects about us. The instruments 
of perception are the five corporeal senses^ see- 
ing^ feelings hearings tasting^, and smelling. 
All the intercourse;, which the mind has with 
the material world^ is carried on by these 
organs. Of the manner^ in which this inter- 
course proceeds^ we have no knowledge. From 
experience we learn^ that a sensible alteration 
takes place in the mind^ w^henever any outward 
object is so situated^ as to affect either of the 
senses. The change^ produced in the mind by 
the impression of the object on the organ of 
sense^ is denominated sensation. The word 



16 PEBCEPTION AND CONSCIOUSNESS. 

perception refers to the knowledge^ that we 
gain by sensation^ of some quality in the ob- 
ject ;^ which knowledge may be retained by 
the mind after the object is removed^ and it 
is then usually called an idea or notion. The 
external object^ or quality perceived^ is de- 
nominated the object of perception^ or the 
archetype of the idea. 

6. If either of the senses be wholly wanting^ 
the mind must be forever destitute of all that 
class of ideas;, which it is the office of that sense 
to furnish. If either be possessed but imper- 
fectly^, the ideas., received from it^ are liable 
to be faint and indistinct. But the usual ef- 
fects of dull organs may be in a great measure 
obviated;, by an increased effort of attention^ 
while the objects are present ; as is manifest 
in the case of persons^ who have had their 
hearing in some degree impaired. 

It is from habitual inattention to our sensa- 
tions^ more than from dulness in the organs 

* " The sensations, which are excited in the mind by ex- 
'* tenisil objects, and the perceptions of material qualities, which 
^' follow those sensations, are to be distinguished from each 
" other only by long habits of patient reflection.'^ Stexvart^ 
Elem, vol. i. ch. v part Sd^ sect. 1st, 



PERCEPTION AND CONSCIOUSNESS. 17 

of sense^ that so few of the objects^ which 
strike our senses, leave anv durable traces in 
the mind ; and that those notions^ which do re- 
main^ are so often obscure and indistinct. As 
the preceptions of sense are the elements of all 
our knowledge^ we should cultivate the habit 
of carefully noticing the things^ which we see^ 
feel^ and the like ; in order that the notions^ 
which we form of them^ may be clear and 
distinct. 

7. Consciousness^ or reflection^ is that notice^ 
which the mind takes of its own operations^ 
and modes of existence."^ By this we are 
made acquainted with the successive chan- 
ges, which take place in the state of our 
minds. Consciousness is similar to percep- 
tion, though the qualities of body, which 
are the objects of the latter, bear no resem- 
blance to the thoughts and operations of 
the mind, which are the objects of the for- 
mer. The mind, at least whilst we are awake^ 
is constantly employed in some mode of think- 
ing, or in some exertion of its powers ; and 
all the operations, passions, and affections of 
the mind, are necessarily subject to its own 

* See note A, at the end of the book. 



18 PERCEPTION AND CONSCIOUSNESS. 

observation. Thus^ by consciousness we learn 
what is expressed by the words compare^ rea- 
son^ doubt^ assent;, joy^ in the same manner^ 
as by perception we gain a knowledge of sweety 
green^, soft^ cold. 

8. Both perception and consciousness^ consid- 
ered apart from any acts of attention^ accompa- 
nying them^ are involuntary states of mind. 
We are often active in bringing external objects 
within our view^ and in varying their position^ 
for the purpose of careful observation ; so^ by 
a voluntary effort, we excite operations^ and 
cause changes in the mind ; but the knowl- 
edge^ that we gain in each case^ of the subjects 
thus presented^ is without any act of the will. 
We cannot avoid hearing many sounds^ and 
seeing the objects^ which are placed before our 
eyes. We are constrained to smell odours^ 
taste our food;, and feel bodies^ when in contact 
with our own. It is the same with respect 
to the operations and states of the mind. We 
are unable to compare^, reason^ abstract ; to 
feel pain^ pleasure^ disgust^ or the likC; without 
being conscious of those states. 



V* 



ATTENTION. 19 



CHAPTER SECOND. 



ATTENTION. 



9. Attentio?t expi^esses the immediate direc- 
tion of the mind to a subject. The distinctness 
of our notions^, the correctness of our judg- 
ments^ and the improvement of all our intel- 
lectual powers^ depend^ in a great degree^ on 
the habitual exercise of this p^ct. Its surpris- 
ing influence^ in improving the perceptive pow- 
ers^ is manifest in persons^ who have been led^ 
by their peculiar callings^ or by necessity, to 
place uncommon reliance on a particular sense. 

Thus sailors^ v^ho are accustomed to look at 
distant objects^ acquire the power of seeing 
and distinguishing things^ which^ by reason of 
their distance^ are invisible to common eyes. 
Musicians become capable of discerning the 
minutest difference in sounds. Cooks and epi- 
cures acquire an uncommon sensibility in tast- 
ing and smelling ; and blind persons improve 
the sense of feeling to such a degree^ as to 
make it^ in some measure^ supply the want of 
sight. These effects are produced solely by 
an increased and habitual attention^ which 



20 ATTENTION, 

enables those persons to notice impressions^, 
which are so slight and languid^ as wholly to 
escape the observation of others. 

10. Attention is considered"^ a voluntary act 
of the vfiind. but it is not at all times equally 
subject to our command^ and in young children 
is wholly involuntary. Extraordinary occur- 
rences^ which awaken curiosity^ and things^ 
which interest us in a high degree^ by exciting 
some violent passion or emotion^ often draw the 
attention so strongly, that we are unable for 
a time to transfer it to any other subject. 
So intensely are we sometimes engaged, that 
we lose our account of time, and take no notice 
of the objects, which strike the senses. 

11. Attention is so essential to memory, that 
without some degree of it no thought could ever 
be recalled ; and the reason why we com- 
mit things to memory more easily at one time, 
than another, is, that we command our atten- 
tion more perfectly. It is equally necessary 
in every operation of comparing, judging, and 
reasoning. Dr. Reid has remarked, *• that, if 
'' there be any thing that can be called genius 

• Stewart, Elements of the philosophy of the mind, vol. i. ch. 
% Reid, Essays on the active powers. Essay II. ch. 3. 



COMPAKING, 21 

^^in matters of mere judgment and reasonings 
it seems to consist chiefly in being able to 
give that attention to the subject^ which keeps 
it steady in the mind^ till we can survey it 
accurately on all sides. There is a talent 
of imagination^ which bounds from earth to 
heaven^ and from heaven to earthy in a mo- 
ment. This may be favourable to wit and 
imagery; but the powers of judging and rea- 
soning depend chiefly on keeping the mind 
to a clear and steady view of the subject.^^^ 

CHAPTER THIUD. 

COMPARING. 

12. When the mind contemplates two things 
in reference to each other^ it performs the op- 
eration of comparing. Thus^ when we say 
iron is harder than lead^ and lead is heavier 
than iron^ we compare these two substances 
with respect to the degrees^ in which they 
possess the qualities of weight and hardness. 
From this operation we derive all our notions 
of relation ; as father^ cousin^ largeness^ small- 
ness, superiority^ subjection^ and the like. 

* Essays on the active powers, Essay 11. cb. 3. 



22 COMPAHING. 

We make comparisons with the greatest ease^ 
and frequently without being conscious of them. 
It is only by this operation^ that v/e are enabled 
to recognise the objects^ which we have be- 
fore known^ or to give ^o any quality or object 
an appropriate name ; for the application of 
the name requires not only the sensation^ pro- 
duced by a present object^ but the comparison 
of that sensation with one formerly felt.* 

13. This operation is performed by children 
in their earliest efforts at speech. It is by 
successively comparing the sounds^ they utter^ 
with those^ made by others^ that they learn to 
pronounce the words of their native tongue. 
That propensity to imitation^, v/hich is always 
conspicuous in the sports of children^ is hap- 
pily calculated to improve this effort of the 
mind. The same may be asserted of many of 
those studies^ which usually occupy the years 
of childhood^ and particularly of the study of 
foreign languages. Translations from one 
language to another require a constant and 
careful comparison of the corresponding words 
of different languages ; an exercise doubly 

• Stewart, Elements, vol. i. ch. 3. 



ABSTRACTION. 23 

important to children^ as it serves to improve 
their discerning faculties^ and at the same time 
leads them to ascertain the exact import of 
words. The correctness of every process of 
judgment and reasoning depends^ immediately 
or ultimately;, on the accuracy of our compar- 
isons. 

CHAPTER FOURTH. 

ABSTRACTION. 

14. Abstraction literally implies the separa- 
ting of one thing from another ; but^ as a men- 
tal operation;, it denotes only a partial consid- 
eration of any thing. It is the act of coiisid- 
ering one or more of the properties or circum- 
stances of an object J apart from the rest. Thus 
we may consider the length of a bridge^ with- 
out regarding its breadth or construction. We 
may speak of fluidity in water^ hardness in 
marblc; or sweetness in sugar^ without noticing 
the other properties of those substances. As 
the quality^ thus mentally separated from 
those existing with it^ may be found in numer- 
ous subjects^ the name applied to it becomes a 
general term. So whiteness stands for the 



24 ABSTRACTION. 

color of snow^ milk^ chalky paper^ and many 
other things. 

15. This power^ which the mind has^ of 
separating the qualities combined in the ob- 
jects^ which fall under our observation^ and of 
tracing the same quality in a multitude of ob- 
jects, is the foundation of all classification ; 
and gives rise to the general words of language. 
But, notwithstanding the necessity of abstrac- 
tion in every act of classification, it may be 
performed on individuals, without referring 
them to any class. This has occasioned some^ 
to suppose, that the formation of classes requir- 
ed a distinct operation, which they called gen- 
eralisation. Dr. Reid says, ^^we cannot gen- 
" eralise without some degree of abstraction, 
but I apprehend we may abstract, without 
generalising. For what hinders me from at- 
tending to the whiteness of the paper before 
me, without applying that color to any other 
object? The whiteness of this individual 
object is an abstract conception ; but not a 
general one, while applied to one individual 
only. These two operations, however, are 

* Reld, Intellectual Powers, Essay V. ch. 3. Collard, Log- 
kk, part I. ch. 2. 



ASSOCIATIOK. 25 

'^ subservient to each other ; for the more at- 
" tributes we observe and distinguish in any 
'' one individual^ the more agreements we shall 
^•discover between it and other individuals/' 

CHAPTER FIFTH. 

ASSOCIATION. 

16. By the association of ideas is understood 
that connexion among the thoughts^ affections^ 
and operations of the mind^ by which one has 
a tendency to introduce another. That one 
idea is often suggested to the mind by another^ 
and that sensible objects revive past trains of 
thought^ are facts familiar to all. Words re- 
call the objects^ to which they have been ap« 
plied ; and the objects as readily suggest their 
names. A long train of associated thoughts 
is sometimes introduced by a single circum- 
stance. The view of the spot^ where we pas- 
sed the first years of life^ after a long absence^ 
will recall many interesting events of child- 
hood. The first notes of a familiar tune^ being 
sounded^ will cause the remaining notes to pass 
through the mind in regular order. 

17. No principle of our nature is produc- 
tive of more important effects, than this^ which 

3 



26 ASSOCIATION. 

establishes a connexion between our ideas;, feel- 
ings^ and mental operations. It is the source 
of numerous errors and prejudices. It is the 
foundation of all our local attachments ; and 
of most of our prepossessions in behalf of the 
government and other institutions of our coun- 
try. It is to the principle of association^ 
that we are to attribute our predilections for 
the modes of dress^ pronunciation^ and behav- 
iour of those;, whom we esteem and respect. 
The principles of association have been dif- 
ferently stated ; but the following are those^ in 
which there is the most general agreement. 

18. Firsts resemblance or analogy is an ex- 
tensive principle of association. We are often 
reminded of one person^ by the countenance^ 
voice^ or gestures of another. One natural 
scene suggests another; and one event or one 
anecdote frequently brings another to our re- 
membrance^ by the similarity we observe be- 
tween them. 

19. Secondly^ opposition or contrast is anoth- 
er principle of association^ but of less exten- 
sive influence^ than the preceding. The pains 
of hunger and thirst suggest the pleasures of 
eating and drinking. Cold reminds us of 



ASSOCIATION. 27 

heat ; darkness^ of light ; and parsimony^ of 
prodigality. So^ among contending parties^ 
extravagance on one side usually drives the 
other to the opposite extreme. 

20. Thirdly^ another^ and with the bulk of 
mankind the most extensive;, ground of asso- 
ciation^ is contiguity^ or nearness of time and 
place. The recollection of an event^ in which 
we were interested^ brings to our thoughts 
many circumstances connected with it^ as the 
place we were in^, when it happened^ or when 
we were informed of it ; the persons^ who were 
with us ; and the peculiar state of our feelings 
at the time. The objects we meet on a road, 
that wx have formerly travelled^ successively 
remind us of the subjects^ about which we 
were employed^ when we passed them before. 

21. A fourth principle of association re- 
sults from the relations of cause and effect^ pre* 
raises and consequences. The sight of a sur- 
gical instrument^ or an engine of torture^ ex- 
cites a strong sense of the pain^ it is calculat- 
ed to occasion ; and the sight of a wound re- 
minds us of the instrument^ by which it was 
made. When we see a fellow being in distress, 
we are solicitous to find out the cause ; and 



28 ANALYSIS^ 

when we have afflictive tidings to communicate^ 
we anticipate the grief, which will be excited. 
22. As one idea may be associated with sev- 
eral others^ each leading to a different series, 
it is obvious, that the same circumstance may 
suggest different trains of thought to different 
persons ; and to the same person at different 
times. The association of ideas is concerned 
in every act of memory and recollection. No 
thought, after it has once passed from the 
mind, could ever be recalled, were it not for 
the tendency of one idea to introduce another.^ 

CHAPTER SIXTH. 

ANALYSIS 

23. Analysis deserves a place among the 
operations, by which the elements of knowledge 
are acquired. Without this, our perceptive 
powers would give us only confused and im* 
perfect notions of the objects around us. To 
analyze is nothing more^ than to distinguish suc- 
cessively the several parts of any compound 
subject. Nature dictates this process. We 

* Hume, Essays, vol. ii. sect. 3. Stewart, Elem. vol. i. ch. 
5. Beattie, dissertations, mor. and crit. vol. i, ch, 2, sect, ii 
Scott, Elem. Intel. Phil. ch. v« sect. L 



ANALYSIS. 29 

commence it at the earliest period of improve- 
ment; and practise it in all our efforts to obtain 
information. The objects^ which nature pre- 
sents to usj, consist of assemblages of different 
qualities^ some more and others less easily dis- 
tinguished. Children early become acquaint- 
ed with the distinguishing properties of the 
things^ daily offered to their senses ; and in a 
few years find out the characteristick marks of 
numerous classes of things^ and learn the use 
of language. 

24. Things^ which have no immediate refer- 
ence to material objects^ such as thoughts^ af- 
fections; and mental operations^ are analyzed 
in the same manner^ as objects of sense. The 
words abstract and reason denote processes of 
thought; each of which may be readily distin- 
guished into separate partS; and these parts in- 
to others more remote. The same may be 
said of moral qualities^ as justice^ prudence^ 
benevolence^ and the like. In these^ as in 
sensible objects^ there are certain parts^ which 
are instantly noticed^ and others^ which are 
discovered by attentive observation. The 
analysis begins in both cases with the leading 

3"^ 



30 ANALYSIS, 

qualities^ and becomes more perfect^ as new 
qualities are discovered. 

25. We employ analysis in interpreting 
symbolical language^ and ambiguous proposi- 
tions. Analysis enables us to investigate caus- 
es by their effects ; and to find out the means 
necessary to attain an end proposed^ by having 
the end first in view. It is by this instrument^ 
that the chemist and botanist retrace the pro- 
cesses of nature^ and ascertain the qualities 
of mineral and vegetable substances. 

Analysis will be further considered undet*^ 
the head of inductive reasoning.* 

♦ CondiUac, Logick, part 1. Watts, Logick, part iv. ch, I. 
Stewart, Elem. vol. ii. cb. 4. 



PAET SECOND. 

OF TERMS AND PROPOSITIONS* 



CHAPTER FIRST, 

LOGICAL DISTINCTIONS OF TERMS. 

26. Words possess no natural aptness to de- 
note the particular things^ to which they are 
applied^ rather than others ; but acquire this 
aptness wholly by convention. Had the con- 
nexion between the name and the thing been 
established by nature^ there would have been 
but one language in the world. But we find 
different words employed in different countries^ 
and with equal advantage^ to signify the same 
thing. Thus white^ albus^ and blanc^ denote 
the same color. The principal distinctions 
of terms in logick are the following. 

27. First, terms are either simple or com- 
plex. A simple term is a single word ; as man, 
horse, tree. A complex term consists of two 
or more words^ representing some object or as- 
sociation^ formed to be the subject or predicate 
of a proposition ;* as human fortitude, a swift 

* See ch. 3. 



33 DISTINCTIONS OF TERMS. 

horse^ an amiable deportment. A wordy which 
denotes several individuals of the same sort^ is 
called a collective term ; as army^ forest^ drove* 

28. Secondly^ terms are distinguished into 
absolute and relative. Ari absolute term is one^ 
which represents an object or quality ^ without 
intimating its relation to any other thing ; as 
man; river^ mountain^ roundness^ strength. 
A relative term denotes an object so far only^ 
as it is connected with some other object. Thus^ 
father implies a man primarily^ as he is con- 
sidered the cause of existence to another indi- 
vidual; denominated; in reference to him^ 
son. These two terms^ intimating each other^ 
by a reciprocal reference^ are called correla- 
tive. So patron and client^ husband and wife^ 
guardian and ward; are correlative terms. 

There are other relative terms; as who; 
which; it; that; and the likc; which barely re- 
call certain other words; before mentioned; 
hence the words they refer to are denominat- 
ed antecedents. 

29. Thirdly; terms are distinguished into 
univocaly equivocal^ and synonymous. Univocal 
terms are suchy as have invariably the same 
signification annexed to them. Thus individ- 



TERMS, 33 

uality, geniis^ electricity^ are univocal terms ; 
for they always signify the same things. 
Equivocal words are suchy as are employed in 
different senses. Of this sort is the word head, 
which may signify a part of a nail, of an an- 
imal, or of a discourse. So the words post 
and shore are equivocal, for they are used 
in various senses. 

That some words should be used in different 
senses is unavoidable, on account of the scanti- 
ness of language, which does not afford a dis- 
tinct name for every idea. Notwithstanding 
this, we sometimes find two or more words ap- 
plied to the same thing ; as wave and billow ; 
dwelling and habitation. These are called 
synonymous terms. 

30. A fourth distinction of terms is into 
abstract and concrete. An abstract term is one^ 
which signijies some quality or attribute ^ with- 
out referring to any subject j in which it may be 
found ; as roundness, hardness, equality, firm- 
ness. Concrete terms denote both the attributes 
and the subjects^ to which they belong. Some- 
times they express the subjects directly j and 
the attributes indirectly ; and sometimes the 
reverse. Thus philosopher, statesman, me- 



34 TERMS. 

ehanick^ are concrete terms^ which directly 
denote persons^ and indirectly^ the attributes^ 
for which they are distinguished. But wise^ 
valiant^ swift^ hard^ are concretes^ immediately 
signifying certain attributes^ and indirectly 
intimating the persons or things^ to which they 
belong. 

31. Fifthly^ terms are either singular or uni- 
versal. A singular term is the proper name of 
some individual person^ place^ or thing ; as 
Alexander^ London^ Danube^ Etna. Proper 
names are given only to those things^ which 
we have frequent occasion to mention^ as 
individuals. The design of proper names is 
to represent these^ apart from the classes^ to 
which they belong. Any term^ that does this 
office^, is a proper name ; and loses not its 
character as such by being applied^ as it fre- 
quently is;, to several individuals of the same 
kind;, as Peter^ John^, William. 

32. Universal terms^ otherwise denominated 
common or appellative^ are names^ indiscrimi- 
nately applicable to many individual beings^ 
whether natural or artificial^ by reason of 
certain properties^ which they possess in com- 



TERMS. 35 

in on. Thus man, city, river, mountain, are 
universal terms, because they agree to all men^ 
cities, rivers, and mountains. 

33. Universal terms make the greatest part 
of the words of every language. Their sig- 
nification is designedly imperfect ; comprising 
only the most common and obvious properties 
of things. They are abridgments of lan- 
guage, happily contrived to facilitate and expe- 
dite the intercourse of society. Every produc- 
tion of nature and art, and every property of 
mind and body, is an individual. Each has 
some properties peculiar to itself ; and others, 
which it possesses in common with many other 
beings. By discarding the peculiar properties, 
and retaining under distinct names those^ 
which are common, we reduce to a limited 
number of classes the innumerable objects, 
which fall under our observation. This dis- 
tribution of things into classes forms what lo- 
gicians call the genera and species of things. 

34. Species denotes a sort or class^ including 
only individuals ; and genus^ a class^ including 
under it two or more species. A species is 
formed by applying a name to that property, 
or collection of properties, in which many in- 



36 TERMS. 

dividuals are found to agree. Thus man is a 
species ; for the name is applicable to an in- 
definite number of individual beings, on ac- 
count of their agreeing in the essential prop- 
erties of an erect figure, and the faculties of 
speech and reason. So horse, deer, eagle^ 
tree, are species. Genus implies the property 
or properties, which diff*erent species possess 
in common. Thus the property of walking on 
four feet is the foundation of the genus quad- 
ruped ; which applies to horse, lion, dog, ele- 
phant, and many other species. So bird is a 
genus, of which eagle, lark, swan, and sparrow, 
are species. 

35. In the distribution of things into genera 
and species, regard is had to the comprehension 
and extension of general terms. By the com- 
prehension of a term^ is meant the aggregate of 
all the known properties of that things or class 
of things^ to which it is applied. Thus gold j 
includes in its comprehension a material sub- 
stance, a yellow color, superior weight, duc- 
tility, fusibility, and every other known pro- 
perty of that body. The extension of a term 
regards the number of individual subjects^ to 

which it may be applied. So the term gold in- 

1 



Vis if 






TERMS. 37 

eludes ill its extension every separate parcel of 
that metal. Man includes in its extension ev-^ 
ery individual of the human race. 

36. Classes are multiplied^ as the conven- 
ience of language is found to require ; nature 
having affixed no limits to the number^ that 
may be formed. As the number of classes in- 
creases^ the names^ which express them^ be- 
come more complicate in their signification^ 
and less extensive in their application to in- 
dividuals. Hence it is received as a maxim in 
logick^ that^ as the comprehension of a general 
term is enlarged^ its extension must be dimin- 
ished ; and the contrary. The comprehension 
of any species is obviously greater^ than that 
of the genus^ to which it is subordinate ; for 
the species includes all the attributes of the 
genus^ and others in addition. Thus^ in the 
following subordinate terms^ swallow^ bird, 
animal^ all the attributes of bird are found in 
swallow, and all those of animal; in bird ; but;, in 
each remove^ a part of the first collection of 
attributes is discarded. The case is different 
with respect to their extension ; that of animal 
is much greater than that of bird^ and that of 
bird greater than that of swallow. 

4 



0*^ 



38 TERMS* 

37* The ranks^ which lie above any class^ 
or which embrace a wider extension^ are cal- 
led^ in reference to it^ superior; and that^ 
which terminates the series, is called most gen- 
eraly or the highest genus. Descending from 
this^ each rank is called inferior ; and the low- 
est class^ which includes only individuals^ is 
called the lowest species. All the intermediate 
ranks^ between the highest genus and the 
lowest species^ are termed subaltern ; each 
being indifferently either a genus or a spe- 
cies^ according as it is considered in the as- 
cending or descending series. Thus bird is a 
genus^ when referred to eagle^ raven^ spar- 
row \ but a species^ when referred to the more 
general term animal. 

38. The genus next above any species is cal- 
led the proximate genus^ and any genus above 
that^ a remote genus of that species. Thus 
quadruped is the proximate^ and animal a re- 
mote genus of horse. The property or collec- 
tion of properties^, by which any species is dis- 
tinguished from every other species of the 
same genus^ is the specifick difference. So juice 
is the proximate genus of wine ; but the cir- 
cumstance of being pressed from grapes is the 



f 



-■4 



DEFINITIOJ^. 39 

specifick diiference^ which distinguishes wine 
from cider and perry^ which are also juices.* 

CHAPTER SECOND. 

DEFINITION A^^D DIVISION. 

39. Definitions are usually distinguished in- 
to two kinds ; one nominal^ or of the name ; 
the other realy or of the thing. A definition 
of the name is merely a specification of the ob- 
ject^ to which a name is applied. A definition 
of the thing is properly an analysis of a things 
or an enumeration of its principal attributes. 

40. Words^ which stand for indivisible ob- 
jects^ admit only of nominal definitions. These 
are sometimes sufficiently explained by intelli- 
gible synonymous words ; thus being denotes 
existence ; identity implies sameness. Those, 
which stand for simple qualities of body, may 
be defined by referring to the subjects, in which 
those qualities reside ; and those, that denote 
mental states, by describing the occasions, on 
which they are produced. Thus yellow is the 

* Locke, Essay on the imderstanding", B. Ill, ch. 3. Tleidj, 
Essays, vol. ii. Essay 5, cb. 1. Belsbam, Logick, part i. sect, 
4 and 5. Kirwan, Logick, part u cli. 2, sect. 2. 



40 DEFINITION, 

color of gold or saffron. Suprise is the pas- 
sion^ or state of mind^ produced by the percep- 
tion of some new or uncommon object. 

41. A real definition leads us to a knowledge 
of the nature of a things by enumerating its 
most essential modes and properties. Thus a 
circle is a figure^ whose circumference is^ in 
every part^ equally distant from the centre. 
Injustice is an intentional violation of anoth- 
er's rights. Real definition includes the nom- 
inal ; for an explanation of the nature of any 
thing necessarily fixes the signification of the 
name^ by which it is called. Natural substan- 
ces, and all compound beings, whether real or 
imaginary, are susceptible of real definitions. 

42. Logicians divide a definition into two 
parts, Vvhich are called genus and difference. 
If the thing to be defined be in any degree 
general, that is, expressed by a generick term, 
the definition will be made up of the proxi- 
mate genus and the specifick difference. Thus 
bird is an animal, which has wings, feathers, 
and a hard, glossy bill. Animal is the prox- 
imate genus, denoting what bird has in com- 
mon with horse, deer, elephant ; the other 
terms denote the specifick difference ; for they | 



DEFINITION. 41 

point out the properties^ which distinguish 
bird from every other species of animals. So 
square is a figure, which has four equal sides, 
and four right angles. Figure is the proxi- 
mate genus ; the other terms make the specif- 
ick difference. 

43. If the thing to be difined be an individ- 
ual, having a proper name, the definition will 
consist of the species and an enumeration of so 
many properties, as will distinguish that indi- 
vidual from all others of that species. Thus 
Mercury is the planet nearest the sun. Plan- 
et is the lowest species ; nearest the sun is 
the circumstance, which sufficiently marks a 
difference between Mercuy and the other plan- 
ets. 

44. There are many woi^ds in every language, 
which cannot be defined, because they have no 
uniform signification affixed to them. The, 
this, that, which, such, every, good, bad, de- 
sirable, and the like, are nearly insignificant 
sounds, till they are applied to particular things, 
from which they borrow a sort of local or tem- 
porary meaning ; and they often signify dif- 
ferent things, when applied to different sub- 
jects. Good, applied to a soldier, means cour» 

4^ 



43 DEFINITION* 

age ; to a Christian^ piety ; to a physician^ 
skill ; to a horse^ stength ; to a knife^ sharp- 
ness. 

45. Words of this description^ which have 
no uniform signification afiixed to them^ are 
wholly employed in the definition of other 
terms. The definitive particles have no other 
iise^ than to restrain the latitude of general 
terms. For example^ the man^ this horse., that 
tree;, such an object. Here the names man^ 
horsc;, tree^ and object^ which represent whole 
classes of things^ are restrained by the words 
the^ this^ that^ and such^ to certain individu- 
als;, with which we are supposed to be already 
acquainted. 

Again^ a wide river^ a severe winter^ a de- 
lightfid prospect. The terms river^ winter^ 
and prospect^ are general ; wide^ severe^ and 
delightful^ denote specifick differences. Where- 
ever the latitude of a general word is restrain- 
ed by a definitive^ or a quality is attributed to 
a subject^ we may recognise the two essential 
parts of a definition^ namely^ genus and differ- 
ence. 

46. Division is the explication of any whole 
by the enumeration of its component parts. 



DEFINITION. 43 

Thus a tree is divided into trunks roots^ and 
branches ; animal^ into beast;, bird^ fish^ and 
insect. The term^ division^ is applicable to 
the resolution of a treatise or discourse into 
its several heads or branches ; also^ to the con- 
sideration of an equivocal word in reference 
to its different significations. 

The members of a division should exhaust the 
subject divided ; and they should be so oppos- 
ed^ that one will not be contained in another* 
The parts^ into which any thing is first divid- 
ed;, should be the largest and most general. 
The resolution of one of these parts into oth- 
ers^ more minute^ is called subdivision. So a 
year is first divided into months. Month is 
then subdivided into weeks ; week^ into days^ 
and so on. Needless subdivisions should be 
avoided^ as they burden the memory^ and in- 
troduce confusion .* 

CHAPTER THIRD. 

GENERAL DESCRIPTION OF PROPOSITIONS. 

47. A proposition is a verbal representation 
of some perception^ acty or affection of the mincL 

* Locke, Essay, B. III. Watts, Logick, part I. Kirvvan^ 
Lo^ick, part I. 



44 PROPOSITIONS. 

The constituent parts of a proposition are the 
subject^ the predicate^ and the copula. The 
two first are called terms^ because they are 
the extremes of the proposition ; and they may 
consist of a single word each^ or of a collection 
of words^ representing some person^ things or 
attribute. 

48. The subject of a proposition is that^ con- 
cerning which something is either asserted^ dc" 
nied^ commanded^ or inquired. The predicate 
is that J which is asserted^ denied ^ or the like^ 
concerning the subject. The copula is thaty by 
xvhich the other txvo parts are connected. 

Body is divisible. 
Man is not omniscient. 
Be ye filled. 
Is C^sar dead ? 

Body^ man, ye^ and Csesar^ are the subjects 
of these four propositions ; divisible^, omniscient^ 
filled;, and dead, are the predicates ; is, is not, 
and be, the copulas. In the first example, the 
agreement between the subject and predicate 
is asserted ; in the second, it is denied ; in 
the third, it is ordered ; in the fourth, it is in- 
quired for. 



■| 



PROPOSITIONS, 45 

49. One part of a proposition is often con- 
tained in another. In the following examples^ 
the copula is contained in the predicate. 

I think. 

The sun rises. 

These imply^ 

I am thinking. 
The sun is rising. 

So the copula sometimes includes the whole^ 
or a part of the predicate ; as Troy was ; that 
is^ Troy was existent. The copula is always 
some inflection of the verb to be^ either ex- 
pressed or understood. 

A single word may contain a complete prop- 
osition. Thus scribo implies ego sum sari- 
bens^ I am writing. So rejoice^ attend^ imply 
be thou rejoicing ; be thou attentive. 

50. The subject of the proposition usually 
stands first^ and the predicate last ; but this 
oi^der is sometimes inverted^ as in the following 
example. 

In China are many ingenious artists* 

That is^ 

Many ingenious artists are [existent] in China, 



46 PROPOSITIONS. 

The words^ which constitute the two terms^ 
are sometimes so blended together^ that the 
whole^ or a part;, of one is placed between parts 
of the other. In the following example^ the 
whole subject intervenes between parts of the 
predicate. 

" But too often different is rational conjecture from 
melancholy fact." Burke. 

In imperative and interrogative propositions^ 
the copula is usually placed first. As^ 

Be thou faithful. 

Is the controversy settled ? 

51* An identical proposition is oncj whose 
subject and predicate are composed of the same 
word or words^ and express precisely the same 
idea. Sometimes the terms are the same^ and 
the ideas different. Thus^ home is home. This 
proposition is not identical^ for home^ as sub- 
ject^ means only a place of residence ; but as 
predicate^ it denotes that it is an agreeable res- 
idence. Sometimes the terms are different^, 
but express the same idea. Thus^ three times 
three are nine ; twelve is the fifth part of 
sixty. Here the terms are reciprocal^, and 
may be substituted for each other ; but the 
propositions are not strictly identical. 



PROPOSITIONS, 47 

CHAPTER FOURTH. 

SIMPLE, COMPLEX, AND MODAL PROPOSTIONS. 

52. A simple proposition is one^ whose sub- 
ject and predicate are composed of simple terms. 

See No. 27. As, 

Time is precious. 
Virtue will be rewarded. 

A complex proposition has one or both of its 
terms complex. They are formed in different 
ways. A proposition is sometimes rendered 
complex, by having for its subject or predicate 
some other proposition, or words equivalent ; 
thus, 

That one man should be punished for the crimes of 
another is unjust. 

The words, which precede is^ and which form 
the subject of this example, obviously contain 
an entire proposition. 

53. Frequently the subject of a proposition 
is first represented by the pronoun zY, and af- 
terwards distinctly expressed ; as in the fol- 
lowing expression ; 

" It is impossible to guess at the term, to which our 
forbearance would have extended,"* 

• Burke, Regicide Peace. 



48 PROPOSITIONS. 

The words^ constituting the real subject^ 
are here represented by the word zV^ which be- 
ing discarded; and the subject stated first^ the 
proposition will read thus^ 

To guess at the term, to which our forbearance would 
have extended, is impossible. 

54. Another manner of rendering a propo- 
sition complex is by introducing the pronoun 
who; which; or that; for the purpose of ex- 
plaining the subject or predicate, ThuS; 

Cyrus, who founded the Persian empire, was the son 
of Cambyses. 

The words; introduced by the relative; form 
a complete proposition; which is called the in- 
cident ; and the whole proposition; including 
this; is called, in reference to it; primary ^ or 
principal. As the design of the incident prop- 
osition is purely to explain the subject or 
predicate of the primary; it can be considered 
only as a part of the term; in v/hich it is plac- 
ed. 

55. Lastly; any proposition is complex; 
whose subject or predicate is defined; by an- 
nexing to it a word of limitation; or restriction. 

AS; 



PflOPOSITIONS^ 49 

Upright men are respected. 
The mind is a simple substance. 

The subject of the first example is defined b;^ 
-the word upright ; and the predicate of the 
second^ by the word simple. These words res- 
train the latitude of the general terms^ men and 
substance^ to which they are joined. They 
are equivalent to incidental propositions^, and 
may be readily resolved into them. Thus;, 

Men, who are upright, are respected. 
The mind is a substance, that is simple. 

56. A modal proposition is ofie^ whose copula 
is qualijied by some word orwords^ representing 
the manner of the agreement or discrepancy be- 
txveen the subject and predicate. The modali- 
ty of propositions is frequently expressed by 
the auxiliary verbs^ may^ can^ must^ oughty and 
the like^ which imply possibility^ necessity^ ov 
contingency. Thus^ 

• Men of influence can do much good- 
Subordination must be maintained. 

The thing asserted^ in each of these proposi- 
tions^ is not the simple and absolute agreement 
of the subject with the predicate^, but barelf' 

5 



OO PROPOSITIONS. 

the nature of that agreement ; namely^ that it 
is possible or necessary.^ 

CHAPTER FIFTH. 

qUALITY AND qUANTITY OF PllOPOSITIONS. 

57. Propositions are further distinguished 
into affirmative and negative ; which has been 
called a distinction with respect to quality. In 
affirmative propositions y the predicate and sub- 
ject are asserted to agree ; as^ 

Clovis was tlie founder of the French monarchy. 

In negative propositions^ the predicate is de- 
clared to be incompatible with the subject* 
This is commonly done by placing the nega- 
tive particle not immediately after the copula. 
Thus^ 

The world is not eternal. 

58. Sometimes the negative particle is plac- 
ed so far from the copula^ that it appears to 
have no immediate connexion with it ; but rath- 
er to belong to some other part of the prop- 
osition. 

JVot all the troops united were able to defend the for- 

ti^ss, 

*Watts, Logick, part II. ch. 2» Kirwan, Logick, part I, ch. 2. 



PROPOSITIONS. 51 

Here the negative word is placed before the 
subject ; but still its influence falls wholly on 
the copula^ and makes the proposition signify 
the opposite of what it would without it. This 
will be evident by stating the proposition thus^ 

All the troops united wei;e not able to defend the for- 
tress. 

59. By the quantity of a proposition is meant 
its consideration in respect to the extent of its 
subject ; and according as the subject is used 
in the whole or a part of its extension^ propo- 
sitions are denominated universal ^v "particular. 
A universal proposition is one^ whose subject is 
a general term^ used in the whole of its exten- 
sion. The signs of universality are all^ each, 
every ^ noy neither^ and the like. Thus^ 

Ml free agents are accountable. 

Every sin is a violation of the Divine law. 

These are universal propositions ; because 
each subject includes an extensive class^ to 
each individual of which the predicate is de- 
clared applicable. 

60. When the sign of universality is omit- 
ted; or the indefinite article is placed before 



5^ PROPOSITIONS. 

the general subject^ the proposition is ealled 
indefinite. Thiis^ 

Planets are continually changing their places. 

A just sovereign regards the welfare of his subjects. 

These subjects are taken in their greatest ex- 
tent; for if there were any planet^ that did 
not change its place^ or any just sovereign^ 
who neglected the welfare of his subjects^ the 
propositions would not be true. 

61. A particulav proposition is one^ whose 
subject is a general tervfij but is taken only in 
a part of its extension. The signs of particu- 
larity are sovfie^ many^ most^ several^ fi'^^ aud 
the like. 

vSome animals are amphibious. 
Many buildings were destroyed. 

The words^ some and many^ restrain the sub- 
jects^ animals and buildings^ and intimate^ that 
a part only of the individual beings^ which they 
include^ will admit the predicates^ amphibious 
and destroyed. 

62. A proposition^ whose subject is the prop- 
er name of some individual person or things is 
denominated singular. As^ 



PROPOSITIONS. 53 

Alfred founded the University of Oxford. 
Stagira was the birthplace of Aristotle, 

A definitive pronoun^ placed before the sub- 
ject of a proposition^, renders it singular. As^ 

That general was defeated. 

The subject of a singular proposition^ as it 
represents only an individual^ is necessarily 
taken in its whole extension ; for v^hich reason 
singular propositions are classed with univer- 
sals. Every proposition therefore is either 
universal or particular. 

63. Besides this quantity in the subject^ 
there is another quantity in the predicate o^ 
a proposition ; for this;, as well as the subject^ 
is taken either in the whole^ or only in a part 
of its extension. The quantity of the subject 
and that of the proposition are the same ; for 
in every universal proposition^ the subject is 
universal ; and in every particular proposition^ 
the subject is particular. But the quantity of 
the predicate depends on the quality of the 
proposition. [See No. 57,] I?i all affirmative 
propositions the predicate is particular ; and in 
all negative propositions it is universal. 

5^ 



54 PROPOSITIONS. 

64. The predicate of an affirmative propo- 
sitioii; separately considered^ is commonly a 
rnqre general term^ than the subject. It is 
usually a genus^ of which the subject is a spe- 
cies. But^ when united to the subject^ no 
greater extension is attributed to it^ than is 
just sufficient to enable it to embrace the sub- 
ject. It is taken in the whole of its compre- 
hension^ but^ in a part only of its extension. 
[See No. 35.] For example^ 

Every dog is an animal. 

Here it is barely asserted^ that the predicate^ 
animal^ does extend so far^ as to include every 
individual of the subject^ dog ; but it is neither 
asserted nor denied;, that it is susceptible of 
a greater extension. Now though the term^ 
animal^ separately considered^ is applicable to 
millions of beings besides dogs^ still in this 
place it has no more extension^ than is express- 
ly given it by the words of the proposition. 
The predicate of every affirmative proposition 
being in this way restrained by its subject^ 
universality can never be attributed to it. 

65. But in negative propositions the pre- 
dicate is taken in the whole of its extension '; 



OPPOSITION AND CONVERSION. 55 

and excludes from itself every individual with- 
in the range of the subject* Thus^ 

No animal is a tree. 
This proposition implies^ that the things^ in- 
cluded under tree^ are so dissimilar to those^ 
included under animal^ that no individual can 
be found^ to which the two terms will apply. 

CHAPTER SIXTH. 

OPPOSITION AND CONVERSION OF PROPOSITIONS. 

66. Opposition in propositions implies a disa- 
greement in respect of quality. Two proposi- 
tions^ which have the same subject and the 
same predicate^ are said to be opposite^ when 
one absolutely denies^ in whole or in part^ 
what the other affirms. There are three ways^ 
in which propositions of this sort may be op- 
posed. First; a universal affirmative may be 
opposed to a particular negative. These are 
called contradictory. As^ 

Every defensive war is just. 

Some defensive wars are not just. 

Secondly^ a universal affirmative proposition 
may oppose a universal negative. These are 
iCalled contrary. As^ 



56 OPPOSITION AND CONVERSION. 

Every disease is contagious. 
No disease is contagions. 

Thirdly^ a particular affirmative may be op- 
posed to a particular negative. These are call- 
ed sub contrary. As^ 

Some amusements are innocent. 
Some amusements are not innocent. 

Two contradictory propositions can never 
be either both true^, or both false^ at the same 
time. Contraries may be both false^ but they 
cannot be both true ; and subcontraries may 
be both true^ but they cannot be both false^ 
at the same time. 

67. The conversion of a ^proposition is the 
transposition of its terms^ so that the subject shall 
take the place of the predicate^ and the predicate 
the place of the subject^ with the preservation of 
truth. When the subject and predicate simply 
change places^ without causing any alteration in 
the quantity of the propositions^ it is called a 
simple co?2version. But ifj in the new arrange- 
ment^ a term of particularity is introduced^ to 
restrain the subject of the derivative propo- 
sition within the same extension^ which it had^ 
as predicate of the original^ this is called a 
particular conversion : by the schoolmen it was 



OPPOSITION AND CONVERSION. 5j 

denominated conversio per accidens. Univet'^ 
sal affirmative propositions are usually conver- 
tible only in the latter mode ; but universal 
negatives and particular affirmatives are con- 
vertible in the former. 

68. The converse of a universal affirmative 
proposition must^ generally speaking^^ be a 
particular affirmative. It is necessary that 
both the terms be taken in exactly the same 
extension^ in both arrangements ; and since by 
the rule^ stated in No. 63^ the predicate of the 
original proposition must be particular^ this 
same term must be particular in the converse^ 
where it is made the subject; which will there-^ 
fore render the j)roposition particular. Thus^ 

Orig, Prop. All swallows are birds. 
Converse. Some birds are sw^allows. 

69. The converse of a universal negative 
proposition is a universal negative. The sub- 
ject and predicate being of equal extent^ mu- 
tually exclude each other; and as these terms 

* This is always the case, except in those propositions, whose 
predicate is a complete definition of the subject. In such 
propositions the subject and predicate are reciprocal ternvs. 
As four times five are twenty: and twenty are four times fiv^. 
Wine is the juice of the grape ; and the juice of the grape is 
wine. 



58 OPPOSITION AND CONVEUSION. 

are both universal in the first arrangement^ 
[See No. 65.] they must be so in the second. 
Thus^ 

Orig. Prop, No deer is an elephant. 
Converse. No elephant is a deer. 

70. Particular affirmative propositions are 
convertible only into the same. In these the 
terms are both particular ; [See No. 61^ 63.] 
and they can never become otherwise by a new 
arrangement. Thus^ 

Orig. Prop, Some birds lie dormant during the winter. 
Converse, Some beings, that lie dormant during 
the winter, are birds. 

71. A particular negative proposition is in- 
convertible in any mode. Its subject is par- 
ticular^ and by conversion this subject would 
be made the predicate of a negative proposi- 
tion^ and must therefore be universal^ accord- 
ing to No. 65 ; a whole deduced from a part^ 
which is impossible. For example ; from this 
proposition^ 

Some birds are not swallows. 

We cannot affirm this^ 

No swallows are birds. 

This would be to deduce a whole from a part; 



COMPOUND PROPOSITIONS. 59 

since swallow is denied of a part only of the 

extension of bird^ in the first proposition ; and 

of the whole of it^ in the last.^ 

72. There is a third species of conversion^ in 

which a negative particle is inserted both in 

the subject and predicate of the derivative 

proposition^ unless previously included in the 

original. This is denominated conversion by 

contraposition. Thus^ 

Ovig. Prop, Every bird is an animal. 
Converse. That, which is not an animal, is not a 

bird. 

These negatives destroy each other^ and the 
proposition is considered as aJBirmative.f 

CHAPTER SEVENTH. 

COMPOUND PROPOSITIONS. 

73. A compound proposition is one^ which has 
two or 7nore subjects^ or predicates^ or both; 
and may be resolvedinto two or rnore propositions* 

* In a universal affirmative proposition, the subject only is 
universal, and the predicate particular ; in a universal negative, 
the subject and predicate are both universal ; in a particular 
affirmative, the subject jiud predicate are botli particular ; and 
in a particular negative, the subject only is particular, and the 
predicate universal. 

t Watts, Logick^part II. ch. 2- Kirwan, Logick, part I. ch.6. 



60 eOMPOtJND PROPOSITIONS. 

As, 

Spring, summer, autumn, and winter, are seasons of 
the year. 

Alfred was prudent, valiant, just, and benevolent. 

As the four subjects of the first example are 
separately applicable to the predicate^ seasons 
of the yeaVy and the four predicates of the last^ 
separately applicable to the subject^ Alfredy 
each may be resolved into four propositions^• 
Thus^ 

Spring is a season of the year. 
Summer is a season of the year, &c. 

74. Every compound proposition may be 
reduced to as many single ones^ as it contains 
subjects, to which the whole predicate will ap- 
ply, and predicates, to which the whole subject 
will apply ; or as there are parts in each^ 
which are separately applicable to each other. 

Beasts, birds* and insects, have life, sense, and motion. 

This example contains three subjects and three 
predicates, and may be reduced to nine dis- 
tinct propositions. 

75. Two or more words are sonietimes so 
coupled together in the subject or predicate, 
as to give the proposition the appearance of 



COMPOUND PROPOSITIONS. 61 

being compound^ when it is single. Thus^ 

Joy and sorrow are opposite qualities. 
Ye cannot serve God and mammon. 

These are complex propositions^ but they are 
not compound ; for neither of them can be re- 
solved into two propositions. The two parts^ 
which make up respectively the subject of the 
one and the predicate of the other^ must be 
taken conjointly. 

76. Compound propositions may be distin- 
guished from those^ that are barely complex^ 
by the following circumstances. First^ in a 
compound proposition^, the parts^ which con- 
stitute the subject or predicate^ are independ- 
ent of each other^ and may be taken separate- 
ly^ as well as conjointly ; which is not the case 
in complex propositions. In the latter^ either 
certain words are joined together^ which rep- 
resent integral parts of some whole^, that is to 
be the subject or predicate^ as three and seven 
are equal to ten ; or one part of the proposi- 
tion is repeated^ directly or implicitly^ by some 
relative word^ as ity that^ who^ which ; or last- 
ly the real subject or predicate is defined by 
an explanfitory word. In either of these cases^ 

6 



62 COMPOUND PROPOSITIONS. 

the words^ which render the proposition com- 
plex^ must be regarded^ as real parts of the 
term; in which they occur. 

77. Secondly^ wherever a complex proposi- 
tion involves a simple one^ there will be the 
distinction of primary and incidental ; and the 
incidental proposition may be false^ while the 
primary is true. But^ in compound proposi- 
tions; there exists no distinction of primary and 
incidental; each part being independent of the 
rest ; and the compound proposition must be 
false; when either of the propositions^ it in- 
volves; is false; though the others be true. 

78. Compound propositions are in most 
books of logick distributed into various sortS; 
denominated copulative^ disjunctive^ conditional^ 
causal^ relative^ and discretive ; which denom- 
inations are taken from the particle; employed 
in the composition of their subject or predicate. 
The examples; already giveii; belong to the 
first class. 

A disjuntive proposition asserts^ that a sub- 
ject agi^ees tvit/i one of two or more named pre d'- 
icatesj or a predicate with one of ttvo or more 
subjects enumerated*^ but does not specify which* 



COMPOUND PROPOSITIONS, 63 

Thiis^ 

Either the sun or the moon will be eclipsed, on Christ- 
mas da J. 

The weather will, at that time, be either clear or cloudy, 

79. A discretive proposition consists of txvo 

parts^ xvhich are contrasted by reason of some 

apparent opposition or inconsistency ^ intimated 

by the particles biitj though^ notwithstanding. 

and the like. As^ 

Hannibal, though unfortunate, was a great general. 
A man may deceive his neighbour, but not his God. 

80. The other distinctions of this class are 
incorrect. What are usually termed condi- 
tional^ causal^ and relative propositions^ are 
nothing more; than different modes of connect- 
ing two entire propositions together. It is es- 
sential to the individuality of a proposition^ 
that it have but one copula. However com- 
pounded or complicated the subject or predi- 
cate may be^ they must be connected by a sin- 
gle affirmation or negation. This rule is vio- 
lated in every instance of what are called coii- 
ditional; causal^ and relative propositions. The 
following have been given^ as examples of these 
kinds, 



64 COMPOUND PROPOSITIONS. 

If the sun be fixed, the earth must move. 
Rehoboam was unhappy, because he followed evil 
counsel. 
As is the Father, so is the Son. 

The first is given as an example of a condition- 
al^ the second^ of a causal^ and the third^ of a 
relative proposition. But neither of them can^ 
with any propriety, be considered as a com- 
pound proposition. Each example consists of 
two entire propositions, possessing distinct sub- 
jects, copulas, and predicates ; and so put to- 
gether, as to constitute a complete act of ra- 
tiocination.^ 

* Collard, Logick, part III. cb. 2. Kirwan, Logick, part L 
ch. 4. Watts, Logick, part II. ch. 2. 



PART THIRD. 



OF JUDGMENT AND REASONING. 



CHAPTER FIRST. 

INTUITIVE EVIDENCE. 

81. Judgment is an act of the mindy uniti?tg 
or separating two objects of thought according 
as they are perceived to agree or disagree,. 
The relation between these objects is sometimes 
discovered by barely contemplating them^ with- 
out reference to any thing else ; and sometimes^ 
by comparing them wdth other objects^ to which 
they have a known relation. The former is 
simple comparison ; the latter is an act of rea- 
soning. The determination of the mind in both 
cases is denominated judgment. Every act 
of judgment is grounded on some sort of evi- 
dence. That^ which determines the mind in 
simple comparison^ is called intuitive evidence ; 
and that; which is employed in reasoning; de* 

ductive. 

6^ 



66 INTUITIVE EVIDENCE* 

The principal kinds of intuitive evidence^ or 
sources of intuitive belief, are the evidence of 
sense^ of consciousness^ of memory^ and of ax- 
iomsy or general pririciples. 

82. The first source of intuitive belief is the 
testimony of the external senses^ hearings seeing^ 
touching^ smelling^ and tasting. These organs 
come to their usual degree of maturity in in- 
fancy, and are employed with equal confidence 
by all descriptions of people. Men have in 
every country, and in every period of the 
world, been governed by their testimony, even 
in their most important concerns. We can no 
more question the existence of the bodies, 
which we see and handle, than we can our own 
existence, or the truth of the most obvious 
maxim, that can be proposed to our thoughts. 
On the evidence of the senses is grounded all 
our knowledge of the nature, powers, and qual- 
ities of the material objects around us. All 
truths relative to physical science or to the 
events of history, and all those rules of pru- 
dence, which relate to the preservation and 
health of our bodies, must ultimately be resol- 
ved into this principle, that things are, as our 
senses represent them. 



INTUITIVE EVIDENCE. 67 

83. Consciousness is another source of intui- 
tive evidence. Its office is to inform us of the 
present existence of our various passions, af- 
fections, and mental operations. The whole 
science of the human mind is built on this evi- 
dence ; and no branch of knowledge stands on 
a surer foundation ; for no evidence is superi- 
or to this, where it is completely ascertained. 
But it is sometimes difficult to define precisely 
the subjects of our consciousness. Those, who 
have not been accustomed to attend to their in- 
tellectual operations, are liable to err in ap- 
plying this evidence. I think, compare, reason, 
doubt ; I feel pain, or pleasure ; I remember 
past events. These are facts, of which I am 
conscious ; and of which I am unable to ques- 
tion the reality. The power of consciousness 
is exercised but imperfectly, till the mind ad- 
vances towards maturity. Some^ have sup- 
posed it to be wholly dormant during the years 
of^childhood. It is however exercised, in a 
greater or less degree, by people of all clas- 
ses ; and the subjects, about which it is em- 
ployed, can be no other, than the mental states 
of a being, which each one calls himself. 

* Scott, Intellectual Philosophy. 



68 INTUITIVE EVIDENCE* 

84. As the evidence of sense furnishes us 
with the knowledge of things present in the 
material world^ and the evidence of conscious- 
ness informs us of whatever is passing in our 
own minds ; so the evidence of memory gives 
us immediate knowledge of things past^ wheth- 
er of a material or intellectual kind. This 
evidence has ever commanded the belief of 
mankind as effectually, as that of sense. Past 
facts and occurrences^ of which we have a clear 
remembrance^ are regarded as certain. This 
is implied by men in all their efforts to gather 
knowledge and improvement from their past 
experience. It is on this principle^ that caus- 
es^ w^hich involve the lives and fortunes of men^ 
are decided by the testimony of witnesses^ in 
courts of justice. Propositions^ formerly prov- 
ed^ may be relied on as present knowledge^ 
though the reasons^ which first gained our as- 
sent to them, be now forgotten^ provided we 
remember^ that we once carefully investigated 
them^ and were then certain of their truth. 
Such propositions must often be introduced or 
referred to^ in demonstrations ; and should 
doubts be entertained respecting their truth^ 



INTUITIVE EVIDENCE. 69 

they must weaken our confidence in the con- 
clusions^ to which they are subservient. Un- 
less therefore the evidence of memory be ad- 
mitted as a ground of certain knowledge^ the 
foundation of demonstrative reasoning w^ould 
be destroyed. 

85. Another species of intuitive evidence is 
that; which accompanies mathematical axioms 
and all those abstract truths^ which carry their 
own evidence with them^ and are readily as- 
sented tO; as soon as they are contemplated. 
ThuS; the whole is greater than a part. Things c 
equal to the same are equal to one another. 
Every effect must have a cause. These prop- 
ositions force our assent by irresistible evi- 
dence^ as soon as we understand the terms^ by 
which they are expressed. They cannot be 
proved; because no principles more evident 
can be assumed^ from which their truth could 
be deduced. In all demonstrative reasonings 
constant use is made of these abstract and self- 
evident propositions.* 

* Beattie, Essay on truth, part I. ch. 2. Stewart, Elem. vol. 
ii. cb. 1. Campbell, Phil. Rhet. vol. i. ch. 5. Scott, Elera. In- 
tel. Phil, ch 8, sect. 3. 



70 DEDUCTIVE EVIDENCE. 

CHAPTER SECOND. 

DIFFERENCE BETWEEN MORAL AND DEMONSTRATIVE 

REASONING. 

86. Reasoning is a process^ by which un- 
known truths are inferred from those ^ xvhich are 
already known or admitted. The evidence^ 
employed in reasoning^, is deductive^ and is dis- 
tinguished into two kinds^ which are^ moral 
and demonstrative* Moral evidence is that 
species of proof which is employed on subjects^ 
directly or indirectly connected with moral con- 
duct. It is not however confined to such sub- 
jects ; but is extended to all those facts and 
events^ concerning which we do not obtain the 
evidence of sense^ intuition^ or demonstration ; 
and to all the general truths^ which are deduc- 
ed from observation and experience.* De- 
monstrative evidence is that^ which is derived 
froin the invariable properties and relations^ 
expressed by general terms. On this distinc- 
tion of deductive evidence is founded the most 
general division of reasoning-, which is into 
V2oral or probable^ and demonstrative. The 

* Gambler, Moral Evidence, ch. 1. 



DEDUCTIVE EVIDENCE. 71 

principal diiferences in these modes of reason- 
ing are the following. 

87. First, they differ in regard to their sub- 
jects. Demonstration is employed about ab- 
stract and independent truths, or those rela- 
tions, which are considered as necessary, and 
whose subjects may be exactly measured and 
defined. The properties of number and quan- 
tity are of this sort. They have no respect to 
time or place ; depend on no cause ; and are 
subject to no change. But the subjects of mo- 
ral reasoning are matters of fact, which are in 
their nature contingent, and the variable con- 
nexions, which subsist among things in actual 
existence. Thus, that mercury may be con- 
gealed by cold, that lead is fusible, that Han- 
nibal led an army over the Alps, that Lisbon was 
once destroyed by an earthquake, and the like, 
are truths within the province of moral reason- 
ing. 

88. Secondly. In a demonstration, it is not 
necessary to examine more than one side of the 
question ; for if any proposition be demonstrat- 
ed to be true, whatever can be offered, as 
proofs on the opposite side, must be mere falla- 



73 DEDUCTIVE EVIDENCE. 

cy. But in cases of moral reasonings there 
are frequently arguments of weight on both 
sides ; and therefore^ in order to judge cor- 
rectly^ we must consider each side of the ques- 
tion; and give our assent to that; on which 
there appears the greatest weight of evidence. 
Thus; having demonstrated the equality of the 
three angles of a triangle to two right ones; 
there is no need of inquiring what may be urg- 
ed against the demonstration. But the case 
is different in questions of a moral kind; as 
whether falsehood may be practised towards 
an assassin ; or whether an oath; extorted by 
violence; be obligatory. In such questions; 
the mind is often perplexed; and the judgment 
held in suspence by the conflict of opposite rea- 
sons< 

89. Thirdly. Propositions; contrary to those 
established by moral evidence; are merely 
false / but those; which are contrary to demon- 
strated propositions; are not only falsC; but 
likewise absurd. ThuS; the assertion; that 
Carthage was never taken by the Romans; 
though falsC; is not absurd ; for there was a 
timc; when it was true. But the assertion. 



DEDUCTIVE EVIDENCE. 73 

that the opposite angles^ formed by two straight 
lines crossing each other^ are not equal; is not 
only false, but also absurd. 

90. Fourthly. In demonstration there are no 
degrees ; the conclusion resulting necessarily 
from the definitions and principles, which have 
been assumed, as the basis of the reasoning. 
But in moral reasoning there is often contrariety 
of evidence, and the degree of assurance, w^e 
feel in the conclusion, must depend on the de- 
gree, in which the evidence on one side exceeds 
that on the other. 

91. Fifthly. In every process of demonstra- 
tive reasoning, the proofs are framed into one 
coherent series, each part of w^hich must have 
an intuitive agreement with that, which goes 
before, and with that, which follows it. The 
longest geometrical demonstration is but one 
uniform chain, the links of which, taken sepa- 
rately, are not regarded, as so many argu- 
ments ; and consequently, w^hen thus taken, 
they prove nothing. But taken together, and 
in their proper order, they form one argument, 
which is perfectly conclusive. In a process of 
moral reasoning, on the contrary, tliere is usu- 
ally a combination of many separate arguments, 



74 BEDUCTIVE EVIDENCE, 

in no degree dependent on each other. Each 
possesses some weighty and bestows on the con- 
clusion a certain degree of probability ; of all 
which, accumulated^ the credibility of the fact 
is compounded. Thus^ the proof^ that the Ro« 
mans once possessed Great Britain^ is made up 
of a variety of independent arguments ; as im- 
memorial tradition ; the testimony of histori- 
ans 5 the ruins of Roman buildings^ camps^ 
and walls ; Roman coins^ inscriptions^ and the 
like. These are independent arguments 5 but 
they all conspire to establish the fact. 

92. Sixthly. It may be further noticed^ that 
the obstacles^ which occur in the practice of 
these two modes of reasonings are of different 
kinds. Those^ which impede our progress in 
demonstration^ arise from the large number of 
intermediate steps, and the difficulty of finding 
suitable media of proof. In moral reasonings 
the processes are usually shorty and the chief 
obstacles^ by which we are retarded^ arise from 
the want of exact definitions to our words ; the 
difficulty of keeping steadily in view the vari- 
ous circumstances^ on which our judgment 
should be formed ; and from the prejudices 
arising from early impressions and associations. 



DEDUCTIVE EVIDENCE. 75 

93. It should be remarked here^ that the 
epithet^ probable ^ as applied by logicians to 
the evidence of moral reasonings has a techni- 
cal meanings altogether different from its usual 
signification. In common discourse^ it is ap- 
plied to evidences which does not command a 
full assent ; but in logical discussions^ it has a 
more comprehensive meanings not only includ- 
ing every subordinate degree of moral evidence^ 
but also the highest. In this latter sense^ it is 
not to be considered as implying any deficiency 
of proofs but as contradistinguishing one spe- 
cies of proof from another ; — not as opposed to 
what is certaius but to what may be demonstrat- 
ed after the manner of mathematicians ; — not 
as denoting the degree of evidences but its jia- 
tiire. It is the more important to keep in mind 
this distinction between the popular and tech- 
nical meaning of the terms probable^ as the neg- 
lect or misapprehension of it has given origin 
to a distrust of moral reasonings as inferior in 
evidence to mathematical demonstration ; and 
induced many authors to seek for a mode of 
proof altogether unattainable in moral inc^ui- 



76 INDUCTION. 

ries 5 and which^ if it could be attained^ would 
not be less liable to the cavils of scepticks.^ 

CHAPTER THIRD. 

INDUCTION. 

94. The first kind of moral reasoning is that^ 
by which we infer general truths from partic- 
ular facts^ that have fallen under our observa- 
tion. This has been called the method of in- 
duction. It is founded on the belief^ that the 
course of nature is governed by uniform laws^ 
and that things will happen in future^ as we 
have observed them to happen in time past. 
We can have no proof of a permanent connexion 
between any events^ or between any two qual- 
ities either of body or mind. The only reason 
for supposing such a connexion in any instance 
is^ that we have invariably found certain things 
to have been conjoined in fact ; and this expe- 
rience^ in many cases^ produces a conviction 
equal to that of demonstration. 

95. When a property has been found in 

* Ried, Intellectual powers, Essay VII. ch, 3» Campbell, Phil. 
Rhet. B. I. cb. 5. sect. 2 Gambler, Mor. Evid. ch. 1. Stew- 
art, Elem. Phil, of Mind, voL i, latrod. part II, sect. 2, voL 
ii. ch, 2. sect. 4? 



INDUCTION. 77 

many subjects of a similar kind^ and no con- 
tradictory instance has been discovered;, though 
diligently sought^ we have an irresistible per- 
suasiou;, that the same property belongs to all 
the individuals of that class. Thus^, having 
applied a magnet to several masses of iron^ and 
found uniformly a strong attraction to take 
place^ we feel no doubt^ that it belongs to the 
nature of iron to be thus affected by that body ; 
and^ though our experience reaches only to a 
small part of the masses of iron in existence^ 
we assert with confidence^ that all iron is sus- 
ceptible of magnetical attraction. So^ having 
often noticed^ that by the application of heat 
to a certain degree^ water is made to boil^ and 
that^ in the absence of heat to a certain degree^ 
it becomes congealed ; and having ascertained 
these changes to be uniform^ so far as they have 
been observed by ourselves and others^ we 
readily ascribe them to the nature of water^ 
and conclude^ that in every country water will 
boil or freeze; on being exposed to those op- 
posite degrees of temperature. 

96. In this way^ by observations and experi- 
ments on individuals of a similar kind^ noticing 
with exactness their agreement^ or the circum- 

7^ 



78 INDUCTION. 

stances^ in which they difFer^ we obtain gener- 
al truths relating to the properties and laws of 
material objects. By the same inductive pro- 
cess we investigate the laws^ which govern the 
phenomena of mind. Thus^ from experience 
it has been ascertained^ that^ when two ideas 
have been often presented to the mind in im- 
mediate succession^ they acquire a tendency 
mutually to suggest each other ; so that, when 
either of them occurs to our thoughts, the oth- 
er readily follows it. We learn also from ex- 
perience, that the durability of past impressions 
on the mind depends greatly on the attention, 
witli which they were at first received. From 
the uniformity of these facts we are taught, 
that contiguity in time or place is a principle of 
association ; and that attention is necessary to 
memory. 

97. As we deduce the common properties of 
a single class of beings from observations on 
individuals of that class, so, by comparing in- 
dividuals of different classes, we discover im- 
portant resemblances between one species and 
another, and are enabled to obtain more exten- 
sive conclusions. Thus, having seen the milk 
of several animals of different species, and 



INDUCTION. 79 

found it uniformly to be white^ we conclude^* 
that the milk of all animals is so. In like man- 
ner^ having witnessed the effect of fire on sev- 
eral pieces of gold^ iron^ lead^ and so forth, 
we affirm, that all metals are fusible. In this 
way, beginning with individuals, we ascend to 
species ; and thence proceed from less general 
to more general conclusions, till we arrive at 
those abstract propositions, which are called 
axioms or general truths. 

98. This method of induction is recommend- 
ed by Lord Bacon, as the first and most im- 
portant instrument of reason, in its search af- 
ter truth. We employ it not only in the inves- 
tigation of general truths, relating to things in 
actual existence ; but in gaining those practical 
rules and maxims, by which the common busi- 
ness of life is carried on. 

99. The use of induction, in learning the 
signification of words, is thus happily explained 
by Mr. Stewart. '^ A familiar illustration of 
'^ this process presents itself in the expedient, 
'' which a reader naturally employs for deci- 
^^phering the meaning of an unknown word, in 
" a foreign language, when he happens not to 
" have a dictionary at hand. The first sen- 



80 INDUCTIOISr* 

^' tence^ where the word occurs^ aifords^ it is 
" probable^ sufficient foundation for a vague 
^^ conjecture concerning the notion^ annexed 
" to it by the author ; some idea or other being 
" necessarily substituted in its place, in order 
" to make the passage at all intelligible. The 
" next sentence^ where it is involved^ renders 
^' this conjecture a little more definite ; a third 
" sentence contracts the field of doubt within 
'' still narrower limits ; till at length a more 
^^ extensive induction fixes completely the sig- 
" nification we are in quest of. There cannot 
" be a doubt^ I apprehend^ that it is in some 
" such way as this^ that children slowly and im- 
^' perceptibly enter into the abstract and com- 
'' plex notions^ annexed to numberless words in 
" their mother tongue^ of which we should find 
" it difficulty or impossible^ to convey the sense 
" by formal definitions/^^ 

100. In another place^ Mr. Stewart has de- 
scribed the manner of using induction^ in 
tracing an event to its physical cause. " As 
^' we can^ in no instance^ perceive the link^ by 
'' which two successive events are connected;, so 

* Philosophical Essays, E^say V. ch, 1. 



INDUCTION. 81 

as to deduce^ by reasoning a priori^ the one 
from the other^ as a consequence or effect^ 
it follows that^ when we see an event take 
place, which has been preceded by a com- 
bination of different circumstances, it is im- 
possible for human sagacity to ascertain^ 
whether the effect is connected with all the 
circumstances, or only with a part of them ; 
and, on the latter supposition, which of the 
circumstances is essential to the result, and 
which are merely accidental accessories or 
concomitants. The only way, in such a case^ 
of coming at the truth, is to repeat over the 
experiment again and again, leaving out all 
the different circumstances successively, and 
observing with what particular combinations 
of them the effect is conjoined.^^ 
" When, by thus comparing a number of ca- 
ses, agreeing in some circumstances, but dif- 
fering in others, and all attended with the 
same result, a philosopher connects, as a gen- 
eral law of nature, the event with its physical 
cause^ he is said to proceed according to th^ 
^* method of induction.^^^ 

* Elements of the Pliilosophy of the Mind, vol. ii. ch.|4sec. 1. 



83 iNDUCTio?>r. 

101. Inductive conclusions will amount to 
moral certainty^ whenever our experience has 
been uniform, and the number of cases exam- 
ined, sufficiently numerous. But this reason- 
ing is liable to be fallacious through impatience 
in the investigation, by which judgments are 
hastily formed, without a sufficient accumula- 
tion of facts. The number of instances, re- 
quired to justify a general conclusion, must be 
increased in proportion, as the facts, from 
which we reason, are more irregular in their 
appearance. In judging concerning the prop- 
erties of inanimate matter, a general inference 
may sometimes be drawn from a small number 
of particular cases. If, for example, aqua for- 
tis has been known to dissolve silver in one in- 
stance, the presumption is very strong, that it 
will do so in all. But the success, which may 
happen to attend a medicine in a single instance, 
furnishes but a slight presumption with regard 
to its general operation on the human body. 

102. When our experience has not been 
uniform, the conclusions we make will fall short 
of moral certainty. An equal number of fa- 
vourable and unfavourable instances leaves the 
mind in a state of suspeuse, without exciting 



ANALOGY. 83 

the smallest expectation on either side. As 
the ratio^ which the instances on the two sides 
bear to each other, may vary indefinitely, so 
must the judgments, founded on them, vary in 
a like degree from the neighbourhood of cer- 
tainty, down to that of entire improbability.* 

CHAPTER FOURTH. 

ANALOGY. 

103. Analogy is the foundation of another 
species of moral reasoning, similar in most re- 
spects to analytical induction. They both pro- 
ceed on the same general principle, that nature 
is consistent and uniform in her operations ; 
so that from similar circumstances similar ef- 
fects may be expected ; and in proportion as 
the resemblance between two cases diminishes, 
the less confidence must be placed in the con- 
clusions, made from the one to the other. The 
word, analogy, is used with much vague- 
ness. Sometimes it denotes only a slight and 

* Bacon, Novum Organiim. lib. i. Campbell, Phil. Rbet. vol. 
i. ch. 5, sect. 2. Beattie, Essay on Truth, part I. eh. 2. sect. 6. 
Tatham, Chart and Scale of Trutli, vol. i. ch. 4. sect 1. Stewart 
Elem. vol. ii. ch. 4. Gambler, Mor. Evidence, ch. 2. Scott, 
liiteL Phil. Appendix, ch. 2. 



84 ANALOGY. 

distant resemblance; as that^ which is found 
between diiferent species of the same genus. 
Sometimes it implies a correspondence of dif- 
ferent relations ; as that^ which exists between 
the fins of a fish and the wings of a bird ; the 
latter bearing the same relation to the air^ that 
the former does to the water. 

104. Inductive and analogical reasoning mk.^ 
so similar in their nature^ that it is not easy to 
point out their specifick difference. The fol- 
lowing circumstances appear to mark a distinc- 
tion^ sufficient to justify their being treated^ as 
separate articles. Firsts induction is a process 
from several individuals of a class to the whole. 
Its conclusions therefore are always general. 
But^ by analogy, we argue from one individu- 
al being to another of the same class ; and from 
one species to another. Secondly^ the evi- 
dence^ employed in analogy^ is wholly indirect 
and collateral ; — the coexistence of two quali- 
ties in one subject affording no direct evidence 
of their coexistence in any other. But in the 
inductive process we have direct evidence^ 
that the property^ which we apply to a whole 
class^ exists in many individuals of that class. 
It is true^ that in all induction analogy must be 



ANALOGY. 85 

used ; for we can never separately examine 
every individual of a whole class^, however 
cautiously we may proceed. So far^ as we ex- 
tend our observations or experiments, the evi- 
dence is direct ; but with regard to the re- 
maining subjects of the classj, the conclusions 
must rest wholly on analogy. 

105. Analogy is an unsafe ground of rea- 
soning; audits eonckisions should seldom be 
received^ without some degree of distrust. 
When things resemble each other in several 
important circumstances^ we are apt to sup- 
pose the similitude more extensive^ than it 
really is. The ancient anatomists^ being hin- 
dered by their superstition from dissecting the 
bodies of men^ endeavoured to obtain the in- 
formation^ which might thus have been deriv- 
ed^ from those quadrupeds^ whose internal 
structure was thought to approach nearest to 
that of the human body. In this v/ay they 
were led into numerous mistakes^ which have 
been detected by the anatomists of modern 
times. 

106. The following is stated by Dr. Reid^ 
as an example of analogical reasoning. " We 
" observe a great similitude between this earth;> 



86 ANALOGY. 

^^ which we inhabit^ and the other planets^ Sa- 
^^turn^ Jupiter^, and so forth. They all re- 
'* volve round the sun^ as the earth does ; 
^' though at different distances and in different 
^' periods. They borrow all their light from the 
" sun^ as the earth does. Several of them are 
" known to revolve round their axes^ like the 
^^ earthy and by that means must have a like 
'' succession of day and night. Some of them 
^* have moons^ that serve to give them light^ 
" in the absence of the sun^ as our moon does 
^' to us. They are all in their motions subject 
" to the same law of gravitation^ as the earth 
^' is. From all this similitude it is not unrea- 
'' sonable to think^ that those planets may^ like 
^^ our earthy be the habitation of various or- 
■'' ders of living creatures. ^^^ 

In the same manner we may conclude from 
analogy^ that the comets are inhabited. But 
this conclusion is less probable^ than the other^ 
in the same proportion^ as the comets have 
less resemblance to this earthy than the plan- 
ets have. 

107. There are many subjects^ both specu- 
lative and practical^ about Vv^hich analogy is 

* Essays on Intellectual Powei^s^ Essay I. ch. 4. 



ANALOGY. 87 

the only evidence we can employ. When a 
lawyer is perplexed with a case^ that falls not 
fairly within the provisions of any existing 
statute^ and for which his file affords no exact 
precedent^ he is placed under the necessity of 
tracing remote analogies and correspondences 
between this case and others within his knov/l- 
edge ; and of forming his method of procedure 
by the equivocal evidence^ furnished by such 
an investigation. To reason correctly on sub- 
jects of this nature often requires more caution 
and discrimination^ than are usually required 
in reasoning on the evidence of testimony or 
experience. ^^It is by the urging of different 
" analogies^ that the contention of the bar is 
'' carried on ; and it is in the comparison^ ad- 
^^ justment^ and reconciliation of them with one 
" another, that the sagacity and wisdom of the 
" court are seen and exercised.^^* 

108. Analogy^ on account of the uncertainty 
which attends its conclusions^ is rarely employ- 
ed in scientifick investigations. It serves to 
guide our judgments^, where direct evidence 
cannot be obtained ; and it affords a degree 
of probability^ which is sufficient for the prac- 

^ Paley, Polit. PhU. ch. 8. 



88 REASONING ON FACTS, 

tical business of life. The proper use of this 
instrument is to defend and illustrate truths^ 
already admitted on other evidence. It as- 
sists to explain ambiguities of language^ and to 
exhibit obscure truths in a clear and familiar 
light.^ 

CHAPTER FIFTH, 

REASONING ON FACTS. 

109. A different mode of reasoning from eith« 
er of the preceding is used^ in the investigation 
of those important and interesting truths^ which 
are comprised under the general name oi facts. 
These are for the most part so unconnected 
and independent^ so transient in their exis- 
tence^ and so dissimilar in the causes^ which 
produce^ and the circumstances^ which attend 
them, that they cannot be deduced from any 
general principles of reasoning. The proofs, 
by which alone they can be established, must be 
derived from impressions, made on the senses 

* Locke, Essay on the Understanding, B IV. cli. 16. Camp- 
bell, Phil. Rliet. vol. i. B. I. ch. 5 sect. 2. Beattie, Essay on 
Truth, part I. ch. 2, sect, 7, Tatham, Chart and Scale of truth, 
vol. i. ch. 1, sect. 3. Stewart, Elem. Phil. Mind, vol. it qh. 4* 
sect 4. Gambler, Mor, Evid. ch» 2. 



REASONING ON FACT^, 89 

of some persons^ to whose immediate observa- 
tion the facts themselves^ or some appearances, 
connected with them^ must have been present- 
ed. The truths^ belonging to this class form 
the largest and most valuable part of our 
knowledge. They enter into the business of 
human life ; and deeply involve the happiness 
both of individuals and communities, 

110. Facts may be distinguished into three 
classes^ in reference to the evidence^ by which 
they are judged. Some are admitted on tes- 
timony alone ; some on circumstantial evidence 
alone ; and some on these two united. 

Firsts human testimony is the evidence^, on 
which we place most reliance for our knowledge 
of such facts^ as have not fallen under our im- 
mediate observation. We readily admit the 
reality of a fact on the sober declaration of a 
person, whose veracity we have no positive 
reason for distrusting. Truth is naturally 
agreeable to the human mind^ for people usu- 
ally speak, as they think. No effort of inven- 
tion is required to relate things as they are ; 
but arts of deception require study ; and are 
seldom practised, but for criminal purposes. 
The moral sense is rarely, if ever, depraved 



90 REASONING ON PACTS» 

to such a degree^ as to lose all preference of 
truth to falsehood. 

111. A propensity to believe what others 
assert has also its foundation in the constitution 
of the mind^ in the same manner as the tenden- 
cy to veracity. Children at first believe ev- 
ery thing, that is told them ; which is a wise 
provision^, as testimony is to them the princi- 
pal means of obtaining knowledge. This dis- 
position to unlimited credulity continues^ till 
experience begets distrust^ and at length teach- 
es the necessity of restraining our confidence 
in testimony within certain limits. 

112. Testimony is either oral or written. 
Oral testimony is distinguished into original^ 
and transmitted or traditionaL It is original 
when it is derived from onej who had sensible 
evidence of the fact asserted. This is the on- 
ly testimony of this kind, in which we can have 
full confidence ; and^ when accompanied by cir- 
cumstances of the most favourable nature^ pro- 
duces a firm belief; even though it be the de- 
claration of a single witness. 

113. When several independent original 
witnesses^ with equal advantages for knowing 
the fact;, which they assert^ and without any 



REASONING ON FACTS. 91 

previous concert^ agree in their report^ they 
mutually strengthen each other^s testimony. 
This concurrence of several independent testi- 
monies is itself a probability^ distinct from 
that^ which may be termed the sum of the prob- 
abilities^ resulting from the separate testimo- 
nies of the witnesses ; a probability^ which 
would remain^ even though the witnesses were 
of such a character;, as to merit no confidence. 
That such a concurrence should be accidental 
is in the highest degree improbable. If there- 
fore concert be excluded^ there remains no 
other cause for the concurrence^ than the ex- 
istence of the fact. 

114. That evidence^ which is professedljr 
given on a certain subject^ is called direct tes- 
timony. But a declaration^ uttered in famil- 
iar conversation^ or casually made in the 
course of a speech or discourse^ may be appli- 
ed as evidence on a subject in no way connect- 
ed with that^ on which it was originally intro- 
duced. This is termed incidental testimony^ 
and it is usually of greater validity than that^ 
which is direct ; because^ from the manner in 
which it was introduced; there is less reason 



92 REASONING ON FACTS* 

to apprehend any deliberate intention to de- 
ceive, 

115. When a witness asserts a fact^ which 
he did not personally observe^ but which he 
received from the mouth of some other person^ 
his testimony is called transmitted^ or tradition- 
al. The general principle with regard to this 
sort of testimony is^ that the further it travels 
from its original source^ that is^ from the im- 
mediate witness of the fact^ the weaker it be- 
comes. The existence of a fact^ reported by 
several persons in succession^ becomes a prob- 
ability, resulting from a series of probabilities^, 
successively founded on each other. Each per- 
son can affirm no more^ than what he received 
from his immediate informant^ and the channel^ 
through which the report was said to have pas- 
sed from the original witness to him. 

116. The circumstances^ constituting what is 
called l\\€ credibility of a witness^ are the follow- 
ing. First^ sufficient discernment^ opportunity^ 
and attention^ to obtain a clear knowledge of 
the fact attested. Secondly^ disinterestedness^ 
which^ in its full extent^ implies the absence of 
all expectation of advantage or detriment, aris- 
ing from the testimony^ either to the witness 



IREASONING ON FACTS% 93 

himself^ or to his friends^ sect^ or party. 
Thirdly^ integrity. This affords the strongest 
assurance of a true testimony, inasmuch as it 
is absohitely inconsistent with any intention to 
deceive or prevaricate;, as well as with a con- 
scious ignorance of the fact attested. To 
these may be added the sanction of an oath^ 
with a knowledge of its nature and of the high 
penalties^ annexed to perjury. But testimony 
under oath is principally confined to juridical 
proceedings. It is rarely employed in settling 
historical facts^ or the ordinary events of hu- 
man life. So far as a witness is deficient in 
either of the above qualifications^ so far will 
this deficiency invalidate his testimony. 

117. Written testimony is usually esteemed 
stronger^ and more deserving of confidence^ 
than oral ; for the record^ being made for the 
most part without a knowledge of the uses^ to 
which it is afterwards applied^ may be presum- 
ed to have been made without any undue bias ; 
and the witness has more time to comtemplate 
the fact^ and weigh the circumstances^ so as to 
render his account accurate. Further^ as the 
record of facts is usually made soon after they 
occurred^ this testimony is secure against any 



94 REASO:NnNG ON FACTS. 

suspicions^ arising from the imperfection of 
memory^ which often weakens the force of oral 
testimony^ especially on subjects of a distant 
date^ where circumstances are liable to be for- 
gotten^ and conjectures substituted in their 
stead. 

118. Written testimony is also less liable to 
have its credibility impaired by transmission^ 
than oral. For^ as the original record is com- 
monly preserved for many years^ it may be 
compared with the successive copies^ and the 
slightest disagreement may easily be detected. 
Whereas oral testimony being fugitive in its 
nature^ the existence of the original witness 
can be proved only by the credibility of the 
second^ and the existence of this^ only by a j 
third^ and so on. Besides^ the care^ which 
copying requires^ gives a copy a preference to 
transmitted oral testimony. Mistake^ unless 
intentional^ is less likely to be committed. 

119. If several independent copies be taken 
of an original record^ and these agree in all 
material circumstances^ their credibility^ with 
respect to the object testified^ is nearly equal 
to that of the original record. For it is highly 
probable^ that the different copies would sub- 






REASONING ON FACTS. 95 

stantially agree; and scarcely possible^ that the 
same error should be committed in all. The 
same remark is applicable to all the successive 
copies^ and the more numerous they are^ the 
more they strengthen each other. 

120. In all plural testimony^ whether oral 
or written^ the several witnesses are required 
to agree in every important circumstance. 

' But in things of minor consequence^ a certain 
degree of discrepancy tends rather to increase^ 
than to diminish^ the credibility of the testi- 
mony ; for such a discrepancy is what must 
naturally be expected from different persons^ 
describing the same things. 

121. General notoriety is a ground of be- 
lief^ extending both to specifick facts and gen- 
eral truths. It is a species of testimony differ- 
ent from either of the preceding in this^ that 
the information is not derived immediately or 
remotely from any one^ who pretends to have 
personally witnessed the fact^ or investigated 
the truth in question. No person can examine 
every subject for himself^ so as to have full 
knowledge of the truth of every proposition^ 
which he finds it necessary to believe. Many 
things must be received on trust. Most meu 



96 REASONING ON FACTS. 

can give no better reason for their belief of 
the greatest part of the facts and general truths^ 
which they receive^ than that they find them 
universally believed by others. 

122. The weight of this evidence depends 
partly on the presumption^ that unless the as- 
sertions were true^ their falsehood would have 
been detected ; and partly on experience ; for^ 
though we are in the constant practice of ad- 
mitting them^ as unquestionable truths^ we 
rarely find ourselves deceived. 

123. This species of evidence should not be 
applied without discrimination. Mathematical 
subjects admit of being certainly known^ and 
mistakes respecting them may be easily correct- 
ed. In these therefore^ propositions^ univer- 
sally believed^ may be relied on with safety. 
The same may be observed of all assertions 
concerning the existence and qualities of ma- 
terial things ; and also concerning those facts 
and events^ which are subject to ihe observa- 
tion of many persons. But the case is differ- 
ent with respect to those propositions^ ♦ which^ 
if false^ could not be easily disproved ; such 
for example^ as relate to events^ which could 
have been observed only by a few persons ; or 






EEASONING ON t'ACTS. 97 

to things^ supposed to have happened in re- 
mote antiquity, or in fabulous ages. Goieral 
notoriety or universal beliefs with regard to such 
propositions, is not a sufficient ground of as- 
sent. 

124. Secondly^ there are many events and 
occurrences, which, as they happen not within 
the notice of any one, can be judged of only by 
a train of circumstances ; and this evidence 
often produces a higher degree of assurance;, 
than the testimony of living witnesses. Cir- 
cumstances can neither falsify, nor withhold 
the truth ; and an event is considered as well 
established, when a number of these are of 
such a nature, that they cannot be satisfacto- 
rily accounted for in any way, but by admit- 
ting the event in question. 

125. Belief, grounded on circumstantial evi- 
dence, is usually A^nomiw^it^ presumption ; and 
presumptions are either slight or violent^ ac- 
cording as the circumstances noticed are more 
or less necessary to the fact supposed, or do 
more or less usually and exclusively attend it. 
Thus, the presumption, that a person is the 
author of an essay, barely because the hand 

writing resembles his, is only slight i for one 

9 



98 REASONING ON FACTS. 

person may imitate the hand of another^ and 
two persons may resemble each other^ in their 
usual manner of writing. But^ to render the 
presumption violent^ the circumstances must be 
such not only;, as w^ould necessarily have at- 
tended the fact^ had it existed ; but such as 
could not be supposed to have existed^ unless 
the fact in contemplation had existed likewise. 
Thus^ a cottage^ discovered on a desolate is- 
land^ affords a violent presumption^ that some 
human being had been there before. A shel- 
ter of some kind would be a natural, if not a ne- 
cessary consequence of a person's having resid- 
ed there ; and there is no other way^ by which 
the existence of the cottage can be accounted 
for. 

The fact^ on which a presumption is ground- 
ed^ must be clearly proved ; for a presumption 
cannot be raised on a mere conjecture. 

126. Thirdly^ the credibility of attested facts 
may be heightened by the analogy of those facts 
to our general experience in similar cases^ or 
to w4iat reason would lead us to expect. This 
analogy is denominated internal evidence. 
Facts, which are rendered probable by inter- 
nal evidence, may have their probability in- 



KEASONING ON FACTS. 99 

creased by testimony^ though in different de- 
grees. If an asserted fact agree with our con- 
stant and invariable experience^ its probability 
can be but little augmented by the most unex- 
ceptionable testimony. Thus^ the freezing of 
water is so common in our climate^ that^ should 
any person affirm^ that Charles river was froz- 
en over in February^ fifty years ago^ we could 
have no hesitancy in believing it. Nor would 
our assurance of the fact be increased^ by the 
united testimony of five hundred witnesses^ of 
the most undoubted veracity. 

127. Where the internal probability is less^ 
more testimony is required to produce belief; 
as if it were asserted^ that there was thunder 
in May^ or frost in October in any particular 
year. These events^ happening not uniformly^ 
though much oftener than they fail^ receive 
but a slight confirmation from past experience. 

128. Those facts^ which are called indiffer- 
ent or equicasualy by reason of the irregularity of 
their appearance^ belong exclusively to the pro- 
vince of testimony ; as, whether a ship sailed 
on Tuesday or on Friday ; whether a man made 
his willj or died intestate. The probability^ 
that any asserted fact of this sort happened at 



100 REASONING ON FACTS. 

any specified time or place^ will be just equal 
to the credibility of the witnesses^ attesting it. 

129. If the asserted fact be of an extraordi- 
nary nature^ and oiie^ that militates with our 
general experience in similar cases^ it will be 
assented to with difficulty ; as^ if it were as- 
serted^ that there was snow in August^ or that 
the same number drew the highest prize in five 
successive lotteries. The internal improbabili- « 
ty of such facts must be overcome by an in- 
creased weight of testimony. 

130. Those facts or events^ which are ad- 
mit^ted with the greatest difficulty of all^ are 
sucb^BS are supernatural^ ov miraculous. These^ 
contradicting our invariable experience^ and 
opposing the well known laws of corporeal nsL- 
.tur% are in themselves in the highest degree 
improbable ; and require for their belief a tes- 
timony so ample^ and attended by such circum- 
stances^ as would render its falsehood no less 
miraculous^ than the fact attested.* 

* Gilbert, Law of Evidence. Kirwan, Logick, Part III. ch. 6. 
Locke, Essay on Understanding*, B, IV. ch. 16. Gambier, Mor- 
al Evidence, ch. 2, 



CALCULATION OF CHANCES. 101 

CHAPTER SIXTH. 

CALCULATION OF CHANCES. 

131. By chance is not meant the negation of 
a cause^ but our ignorance of it. Every change in 
the universe must proceed from some adequate 
cause. When we speak of events^ as happen- 
ing yor/^^if(9z/^/z/^ or by chanccy we mean no more^ 
than that the causes^ which produce them^ are 
wholly unknown to us. The bare possibility 
of an event is often denominated a chance ; and 
where there are several known causes equally 
capable of producing different events^ it is man- 
ifestj that there are so many chances of those 
events ; and that no one of them is more prob- 
able than the rest. 

132. The doctrine of chances is that^ which 
teaches the degree oj* probability or improbahih 
ity of any one of a given number of events ^ con- 
sidered as equally possible. Thus^ on throwing 
a dicj it is certain that some one of its six fa- 
ces will be turned up ; bot^ as only one of these 
six faces can present an ace^ the chance of throw- 
ing an ace is only one out of six chances, or ^% 
and the chances against it are five out of six, 

or J- of a certainty. Hence the general rule 

9^ 



102 CALCULATION ^t CHANCES^ 

is^ that the probability or improbability of any 
event is^ as the number of the favourable chances^ 
divided by the sum of all the chances^ both fb- 
vourable and unfavourable. 

133. The degree of probability^ that any 
event will or will not happen^, is conveniently 
expressed by a fraction;, whose numerator rep- 
resents the number of chances^ which favour 
the existence^, or the nonexistence of the event ; 
and whose denominator is the sum of all the 
chanceS;, both favourable and adverse to the 
event. Thus^ if an event have five chances to 
happen and three to fail^ the fraction |- will ex- 
press the probability of its happening, and the 
fraction |-, that of its failure. These two frac- 
tions, which represent all the chances both of 
happening and failing, being added together, 
their sum will always be equal to unity ; since 
the sum of their numerators wall be just equal 
to their common denominator. And as in every 
case it is certain, that an event will either hap- 
pen or fail, it follows, that certainty is justly 
represented by unity. 

134. The expectation of obtaining a benefit, 
which depends on the happening of an uncer- 
tain ev^nt, has a determinate value before the 



CALCULATION Or CKANCES. 103 

event takes place. The value of this expecta- 
tion is in all cases estimated by multiplying the 
value of the benefit expected^, by the fraction^ 
which represents the probability of obtaining it. 
Thus^ if 60 crowns be promised a person on 
condition of his throwing a particular face on 
a die^ his expectation before trial is worth 10 
crowns, since he has one chance in six^ or |* of 
a certainty of gaining the whole sum. 

135. Events are either independent or de- 
pendent. Two events are independtnt^ when 
they have no connexion xvith each other ^ and the 
happening of one neither promotes nor hinders 
the happening of the other. Thus^ throwing 
an ace on one die affects not the possibility of 
throwing it again on the same^ or on another 
die. But the possibility of ^ joint event on two 
dice^ though each is independent of the other^ 
singly considered;^ is affected by all the possi- 
bilities of failure in each of the conjoined events. 
Now there are thirty six possible events on 
two dice considered conjointly ; for each has 
six faceSj and each face of the one may be com- 
bined with each face of the other. Therefore 
the possible appearances are 6x6=1=36. But 
of these combinations there is but onC; pro^ 



104 cittJutATION OF CHAXCE^. 

diictive of the appearance of two aces^ or any 
other two faces. So that the chance of throw- 
ing two aces either together on two dice, or 
successively on one die^ is only ~. 

136. Hence the probability of two or more 
independent but joint events is equal to the 
product of the chances of each. Thus^ the prob- 
ability of throwing three aces successively on 

one die is -J x ^ X ■§- = ttt* ^^ ^^ ^^^ probabil- 
ity^ that one man^ A^ will live a year^ be -^^ 
and the probability of the life of another man^ 
B^ for one year^ be ~^ the probability^ that 
both will live another year^ is but -rs- X ~ == 
■^^. Hence the concurrence of two events is 
less probable^ than the occurrence of either ; 
and is even improbable^ though each is probable 
and completely independent of the other. 

137. From the foregoing rule it is manifest^ 
that the joint occurrence of two or more equi- 

teasual; independent events^ is improbable ; and 
tiie more so^ the more numerous they are. For 
^the probability of each is -^ ; therefore the joint 
chance of two such events is ^-^ t- t5 ^^^^ ^^ 
three such events is 4- " -^ ^ - ~. So the con- 
currence of two independent^ improbable facts 
is still more improbable. For supposing the 



qALCULATION OF CHANCES. 105^ 

improbability of one of them to be -|^^ and that 
of the other -j^ their joint improbability would 
be -^. B)^ the same riile^ the improbability 
of the death of A within a year being -^-^^ and 
that of the death of B within a year —, the im- 
probability^ that both will die within a year^ 

^s "ts-XiV-tI^- ^^d the probability that 
one of the events will happen and the other fail 
is^ as the probability of the happening of the 
one, multiplied by the probability of the failure 
of the other. So in the above case, the prob- 
ability, that A will live and that B will die, 
is ~ X -rs- = tVo • -^^d the probability, that 
B will live and that A will die, is ~ x tV = 

3 a 



I o o* 



138. A dependent event is one^ whose exist- 
ence is rendered more or less probable by the 
chances J attending the existence of another event. 
When several events are connected in such a 
manner, that the second depends on the first, 
the third on the second, and so on, the prob- 
ability of the first or independent event must 
be first ascertained ; that of the second, which 
depends on the first, is then found, by mul- 
tiplying its separate probability into that of 
the first 5 and the product will give the real 



106 CALCULATION OF CHANCES. 

probability of the second event. In the same 
manner we proceed to find the probability of 
a third or fourth dependent event. 

139. Thus^ suppose six white and six black 
balls to be placed in a box^ and^ through a hole 
in the box^ two balls to be successively drawn 
out ; and let it be required to determine the 
probability^ that both these will be white. As 
there are twelve balls in the box^ and six of 
them are white^ it is evident, that the proba- 
bility of drawing a white ball at the first trial 
will be ~. But the chance of doing this on 
the second trial will be difi'erent ; for^ as one 
of the balls has been taken out^ there are but 
eleven remaining ; and since^ in order to the 
second trials it is necessary to suppose^ that the 
ball removed was a white one^ the remaining 
number of these is reduced to five. The sep- 
arate probability therefore of drawing a white 
ball at the second trial will be only -^- ; and 
the chance of drawing it the first and second 
time will be ~z=i^x~'=--h:* "The separate 
probability of drawing out a white ball at a 
third trial^ since two white balls have been re- 
moved^ will be yV 5 ^^d the chance of drawing 
three white ones at three successive trials will 
be — >^ -^ X' -^ — 



a o 1 



CALCULATION OF CHANCES. 107 

140. Again^ W sailed for Africa in a fleet 
of twelve ships^ three of which were lost in a 
storm^ on the first part of the voyage. Of the 
crews of the nine ships^ that escaped the storm^ 
one third part perished from the hardships^ 
they met on the voyage ; we wish to ascertain 
the probability^ that W has escaped both ca- 
lamities. Now as the chance of his having sur- 
vived the hardships of the voyage depends on 
the event of his having escaped the storm, the 
probability of the last named event must be 
first ascertained. If this be found improbable^ 
the second event must fail ; but if it be found 
probable^ the second event may exist, and the 
probability of its existence may be found by 
the rule already given. [No. 138.] 

141. As nine ships out of the twelve surviv- 
ed the storm, the probability that W escaped 
in one of them is yt=4- This being suppos- 
ed, the probability of his having escaped the 
second danger, since only one third of those^ 
who survived the storm, perished, is y. Hence 
the probability of his having lived through 
both dangers is ^ x y == yt = t- Therefore it 
is merely doubtful whether he survived both 
calamities. If only \ of the crew survived the 



108 BEMONSTRATITE REASONING. 

second danger^ then his escape would be improb- 
able; for^x.^ = YV- I^ ^^^y ^^^^ out of the 
twelve ships were lost^ and consequentlj^ ten 
had escaped the first danger^ and ~ of the crew 
had escaped the second danger^ as above^ then 
the probability of his entire survival would be 
TT X T^ yl- - i ; a slight probability.^ 

CHAPTER SEVENTH. 

GENERAL DESCRIPTION OF DEMONSTRATIVE REASONING. 

142. The general nature of demonstrative 
7^easo?iing has already been explained^ in point- 
ing out the circumstances^ which distinguish it 
from moral^ or probable reasoning. See No. 
87 to 93. It has generally been admitted^ that 
demonstration can be employed only about such 
truths^, as have been termed necessary^ the 
subjects of which are not supposed to have any 
real existence^ but to be abstractly conceived 
by the mind. All created beings depend on 
the will of their Creator. Their existence^ 
their properties^ and of course the relations^ 
subsisting among those properties^ are contin- 

* Demoivre, Doctrine of Chance.?, Iiitrodiictiom KIrv/aB, 
Logick, part III. cli. T. 



DEMONSTRATIVE HEASONING. 109 

geiit^ and perpetually varying. Our reason- 
ing on these must be grounded on the observa- 
tion of our senses ; and the conclusions^ which 
we make, are liable to be uncertain. But de- 
iipionstrative reasoning, being grounded on 
exact and adequate definitions, and proceed- 
ing by the successive application of general 
propositions, which have an intuitive agree- 
ment with each other, affords satisfaction in 
every step ; and the mind advances to the 
conclusion with the fullest assurance of certain- 

143. Demonstration is best adapted to the 
exact sciences of number and quantity. Arith- 
metick and geometry possess many important 
advantages with respect to this method of rea- 
soning. Their terms are free from all ambi- 
guity. Their first principles are simple and ob- 
vious. The subjects, about which they are 
conversant, are wholly independent of things 
in actual existence ; and capable of being per- 
fectly defined. The properties, belonging to 
these subjects, and their various relations, are 
necessary and immutable. These circumstan- 
ces impart to mathematical demonstrations a 

clearness and force, which cannot be obtained 

10 



110 DEMGNSTRATIVE REASONING. 

in other sciences. For these reasons many 
have maintained^ that demonstrative reason- 
ing can be used only within the precincts of 
mathematicks. Many others have controvert- 
ed this position ; and have contended^ that this 
method may^ at least occasionally^ be employ- 
ed in other sciences. 

144. Mr. Locke advanced the opinion^ that 
moral subjects are as susceptible of demonstra- 
tion^ as mathematical. His reason for this 
opinion is thus stated in his Essay on the Un- 
derstanding.^ " The precise^ real essence 
" of the things^ moral words stand for^ may be 
" perfectly known ; and so the congruity or 
^' incongruity of the things themselves be cer- 
'^ tainly discovered ; in which consists perfect 
" knowledge.'^ He adds^ " definition is the on- 
" ly way whereby the precise meaning of mor- 
^' al words can be known ; and yet a way^ 
'' whereby their meaning may be known cer- 
" tainly^ and without leaving any room for con- 
" test.'^ In another placef he says^ ^^ the re- 
^Hation of other modes may certainly be per- 
" ceived^ as well as those of number and ex- 

* Book III. ch. 11, sect. 16. 
t Book ly. ch. 3, sect. 18, 



DEMONSTRATIVE REASONING 111 

^^ tension ; and I cannot see why they should 
" not also be capable of demonstration^ if due 
'' methods were thought on to examine or pur- 
^^ sue their agreement or disagreement.'^ 

145. Dr. Reid distinguishes demonstrative 
reasoning into two kinds^ which are metaphy- 
sical and mathematical. ^^In metaphysical 
*^ reasoning^'' he observes^ '^ the process is al- 
^' ways short. The conclusion is but a step or 
'^ two^ seldom more^ from the first principle or 
^*' axiom^ on which it is grounded ; and the dif- 
^^ ferent conclusions depend not one upon an- 
^' other. It is otherwise in mathematical rea- 
^' soning. Here the field has no limits. One 
^' proposition leads to another ; that, to a third;, 
^^ and so on without end. If it should be ask- 
^^ ed^ why demonstrative reasoning has so wide 
^^ a field in mathematicks^ while^ in other ab- 
^^ stract subjects^ it is confined within very nar- 
^^row limits ; I conceive this chiefly owing to" 
^^ the nature of quantity ;, the object of mathe- 
'' maticks.^'^ 

146. Demonstration^ in the customary sense 
of the term^ appears not to be absolutely cir- 
cumscribed by the narrow limits of a single 

* Essays on the Intellectual Powers, Essay VIL ch. 1. 



112 DEMONSTRATIVE R:^AS0NING, 

science. Wherever the subjects of our reason- 
ing are independent on the existence of things^ 
and are of a nature to afford exact definitions 
and general propositions of undoubted certain- 
ty^ there this method of reasoning may be em- 
ployed. And it appears unnecessary to con- 
(iede, that these elements of demonstration are 
no where to be found^ except in the science of 
mathematicks. 

147. Professor Scott^ speaking of Dr. Reid^s 
division of demonstrative reasonings says ; ''It 
" evidently cannot be meant by Dr. Reid^ that 
" metaphysicks is a science demonstrable in all 
^^its partS;, like mathematicks. He was too 
'' well acquainted with the general uncertainty 
" of metaphysical speculations to have advano- 
'' ed such an opinion. If then he asserts only^ 
" that several metaphysical truths admit of 
'' demonstration^ the same ought doubtless to 
'' be said of physicks^ many of the reasonings 
" of which have at least as much of demonstra- 
" tive certainty, as any of the speculations of 
^^metaphysicks. The truth appears to be, 
'' that every branch of science may occasionally 
" assume the demonstrative form. The exist- 
" ence of a Deity, the immateriality of the hu- 



DEMONSTRATIVE REASONING, 113 

'' man soul^ and other moral or metaphysical 
" truths have perhaps been as fairly demon- 
" strated^ as the Pythagorean proposition^ or 
^^the parabolick motion of projectiles. But 
^^some sciences are much more susceptible of 
" this kind of proofj than others ; physicks ad- 
" mitting much more of demonstration^ than 
'^ metaphysicks^ or morals. Of all the sciences^ 
" mathematicks is that;, which admits the most 
" largely of demonstration. Its first principles 
" are so certain^ so definite^ and clear ; and its 
^^ manner of proof so accurate and legitimate^ 
" that it may fairly be called a completely de- 
^' moDstrative science^ and the only one^ which 
" is justly entitled to that name.^^'^ 

CHAPTER EIGHTH. 

DISTINCTIONS OF REASONING. 

148. Reasoning is further distinguished in- 
to that^ which is a priori^ and that^ which is a 
posteriori. Reasoning a priori is that^ which 
deduces consequences from definitions formed^ 
or principles assumed ; or which infers effects 
from causes previously known. The books of 

* Elem. of Intell. FhiL ch. 8. sect. 4. 



114 DISTINCTIONS OF REASONING* 

mathematicks afford numerous instances of con- 
clusions legitimately drawn from definitions 
and assumed principles. We also reason a 
priori whenever we judge of effects from a 
knowledge of the causes^ which produce them. 
Thus we infer^ that an eclipse of the sun and 
an eclipse of the moon can never happen with- 
in twelve days of each other^ from our knowl- 
edge of the causes^ which occasion those phe- 
nomena. 

149. Reasoning a posteriori is the reverse of 
the former process. By this we deduce causes 
from effects. Thus we infer^ that the earth is 
spherical from its shadow on the moon in a lu- 
nar eclipse ; and we infer the being of a God 
from our own existence and that of the objects 
around us. All reasoning concerning the prop- 
erties and laws^ both of mind and body^ pro- 
ceeds on this principle. It is only by a care- 
ful observation of facts^ that the laws^ which 
regulate them^ can be discovered. 

150. Another distinction of reasoning is^ in- 
to direct and indirect. The reasoning is direct^ 
when the proofs are so applied^ as to show im- 
mediately the agreement or repugnancy between 
the subject and predicate of the proposition in 



DISTINCTIONS OF REASOisTlNG. 115 

question* In indirect reasonings the argU" 
ments^ which we employ^ are not intended 
primarily to show the relation between the terms 
of the proposi Lionel whose truth we would es- 
tablish ; but to prove the falsehood or absurd- 
ity of the proposition^ to which it is opposed. 
This method may be adopted, whenever it is 
manifest^ that the proposition;, which we allege^ 
or its contrary^ must be true. We may then 
prove the impossibility of the contrary propo- 
sition ; or we may show^ that a manifest ab- 
surdity must follow from admitting it ; and in 
either case we establish the truth of our orig- 
inal proposition. The former course is usually 
called a proof per impossibile ; and the latter^ 
a reduetio ad absurdum. 

151. Mathematicians make frequent use of 
indirect reasoning. Thus^ Euclid proves by 
an indirect course^ that^ " if two circles touch 
" one another internally^ they cannot have the 
" same centre. ^^ He first supposes the contra- 
ry to be true^ namely^ that the two circles have 
the same centre ; and no third supposition can 
be made^ for they must either both have the 
same centre or not. He then demonstrates the 
impossibility of the case assumed 5 and thence 



116 SYLLOGISTIC REASONING, 

infers the truth of the proposition^ which he 
first asserted. So moralists prove the existence 
of an all-wise and powerful Creator^, by tracing 
the absurdities^ which the contrary supposition 
involves, 

152. Another form of indirect reasonings in 
frequent use^, is denominated reasoning a forti- 
ori. This consists in deducing a proposition^ 
as true^ from less obvious propositions^ embrac- 
ed by the same general principles. Thus^ if 
the felon^ who robs on the highway^ deserves 
the punishment of deaths this retribution is due 
a fortiori to the wretch^ who has committed 
parricide. 

CHAPTER NINTH. 

GENERAL DESCRIPTION OF SYLLOGISTICK REA- 
SONING. 



153. All reasoning proceeds by comparison; 
and two comparisons are necessary to enable 
us to make a conclusion. The subject and pre- 
dicate of the proposition to be proved must be 
separately compared with some third term^ or 
common measure ; and from these comparisons 
we infer their agreement or repugnancy. This 
process, when expressed in words; consists of 



SYLLOGISTIC REASONING, 117 

three propositions^ and has been termed syllo- 

154. Syllogism was regarded for many centu- 
ries, as the only sure instrument of reasoning ; 
and skill in the use of it^ as the highest ac- 
complishment^ which the mind can possess. It 
derived its celebrity from the talents and indus- 
try of Aristotle^, who traced and analysed its 
principles^ subjected it to lawS;, and exhibited 
it in all the variety of modes and figures^ into 
which it could be moulded. Since the time of 
this philosopher^ the name^ syllogism^ has usu- 
ally been employed to denote an argumenti, 
framed according to certain technical rules of 
art. But it is sometimes used in a larger sense 
to imply any process of reasoning from more 
general to less general^ in opposition to the 
principle of analytical induction. In this sense^ 
it will apply to mathematical reasoning ; for 
all demonstrations in this science proceed on 
this fundamental principle of the syllogism^ 
that whatever may be ajffir^med of any genuSp 
may be affirmed of all the species^ included iin* 
der it. 

tiocinoi% computo. 



118 SYLLOGISTICK REASONlK^G. 

155. Syllogism and induction proceed in op- 
posite directions. Induction^, as has already 
been observed^ begins with individual objects^ 
as they exist in nature^ and ascends by succes- 
sive steps to the most general truths. Syllo- 
gism begins where induction terminates. It 
commences with some universal proposition^, 
and follows back the footsteps of the former 
process^ transferring at each stage the predi- 
cate of the more general^ to the less general 
rank of beings ; or^ in other words^ predicat- 
ing the genus of the species^ and the species of 



4 

156. The difference of these methods may 
be shown by the following example. We ob- 
serve that the individual people of our acquaint- 
ance are constantly dying around us ; that mei 
rarely live to the age of an hundred years^ and] 
that the former generations are wholly swept' 
from the earth. From these facts we infer^ 
that death is the common lot of our species. 
Observing also^, that the same fatality attends 
the various species of beasts^ birds^ and insects^ 
we deduce the more general conclusion^ that all 
animals are mortal. This inductive process^ 
reversed in syllogistick language^ would run 
thus ; 



SYLLOGISTICK REASONING. 119 

All animals are mortal ; 
All men are animals ; 
Therefore all men are mortal. 

All men are mortal ; 
W. X. Y. are men ; 
Therefore W. X. Y. are mortal. 

157. Syllogism is employed with advantage 
in communicating to others^ in an exact and 
perspicuous manner^ the general principles of 
science. It is also of service in exposing the 
weakness of arguments^ stated in loose or fig- 
urative language. But it is of no use in help- 
ing us to the discovery of new truths. We 
must know a thing firsts Mr. Locke observes^^ 
and then we can prove it syllogistically. 

158. As syllogism operates wholly on gener- 
al propositions^ and definitions previously es- 
tablished^ the justness of its conclusions must 
depend ultimately on the accuracy^ with which 
the inductive processes have been conducted. 
" The syllogism/^ says Lord Bacon^ " is form- 
" ed of propositions ; propositions^ of w ords ; 
" and words are the marks of ideas. If there- 
" fore ideas themselves^ w^hich make the ground- 
"^^work of our reasoninQ:s9 are confused, and 

' ESf:av,B. IV. ch. 17. 



120 REGULAR SYLLOGISMS, 

^^ formed from a hasty observation of things^ 
^' the conclusions^ which we make from them^ 
^' will be without solidity. The whole there- 
'' fore depends on the accuracy of our induc- 
^' tions.'^^ 

CHAPTER TENTH. 

OF REGULAR SYLLOGISMS. 

159. The most general division of syllogisms 
is into single and compound. Of single syllo- 
gisms some are regular and some are irregular. 
A regular syllogism is an argument^ consisting 
of three propositions^ the last of which is deduc- 
ed from the two preceding ^ and is substantially 
contained in them. Example. 

Every human virtue should be habitually practised ; 
Industry and temperance are human virtues ; 
Therefore industry and temperance should be habitually 
practised. 

160. This is a concise and luminous method 
of evincing the agreement or repugnancy be- 
tween the subject and predicate of a proposi- 

* *^ Syllogismiis ex propositionibus constat ; propositiones, ex 
*' verbis; verba notionum tesseree sunt. Itaque si notiones ipsae, 
" id quod basis rei est, confusae sint, et temere a rebus abstractae^ 
^' nihil in iis, quae superstruuntur, est iirmitudinis. Itaque spes est 
una in inductione vera," Novum Organum, Lib. 1 Apb. 14. 



e 



REGULAR SYLLOGISMS. 121 

tioii. A third term^ having a common relation 
to them both^ is invented;, and applied to them 
successively^ in two distinct propositions. 
These are called "premisesj because from them 
the proposed question is inferred^ as a conclu- 
sion ; and its subject and predicate are either 
joined or separated^ according as they wer 
found in the premises to agree^ or not^ wi 
the term introduced. It is obvious^ that^ if 
any two things agree with a third^ they must 
agree xvith each other ; and that txvo things^ of 
which one agrees^ and the other disagrees^ with 
a thirdj must disagree with each other. The 
former of these rules is the foundation of all 
affirmative conclusions^ and the latter^ of all 
negative. 

161. The names of the three propositions 
are the major^ the minor ^ and the conclusion. 
These are composed of three terms^ denominat- 
ed the major^ the minor ^ and the middle terms. 
The predicate of the conclusion is called the ma- 
jor termJ^ because it is the most general ; and 
the subject cf the conclusion^ the minor term^ 
because it is the least general. These two are 
also denominated the extremes ,- and the third 

* See note B, at the end of the book. 
11 



123 KEGULAR SYLLOGISMS. 

tenuj introduced as a common measure be- 
tween tliem^ is called the mean or middle term^ 
because its extension is less than that of the 
major, and greater than that of the minor term. 
[See No. 35.] This circumstance proves the 
natural situation of the middle term to be that 
of subject in the major premise^ and of predi- 
cate in the minor ; since the predicate of a 
proposition is never less^ but usually more gen- 
eral^ than the subject. 

162. In forming the syllogism^ each term is 
taken twice^ and no more. The middle and 
major terms constitute the major premise ; the 
minor and middle terras^ the minor premise ; and 
the two extremes^ connected by a copula^ make 
tip the conclusion. The major proposition 
must always be universal^ but may be either 
affirmative or negative ; and the minor prop- 
osition must always be affirmative^ but may 
be either universal or particular.^ The conclu- 
sion may be either universal affirmative^ uni- 
versal negative^, particular affirmative^ or par- 
ticular negative. 

163. In every regular syllogism^ the major 
proposition is placed first ; the minor, next ; 

* See note C^ at the end of tlie bcolc. 



REGULAR SYLLOGISMS. 123 

and the conclusion^ last ; as in the following 
example. 

Every vegetable is combustible ; 

Ever J tree is a vegetable ; 

Therefore every tree is combustible. 

Combustible is the major term ; every tree^ the 
minor term ; and these extremes are joined in 
the conclusion. Vegetable is the middle term ; 
it is subjected in the major premise^ and pre- 
dicated in the minor. The major premise must 
always be sufficiently general to involve the 
conclusion ; and must be assumed^ as a truth 
already known. It cannot be proved by syllo- 
gism. This instrument teaches only how to 
make a legitimate inference of one proposition 
from another. 

164. The truths proved by the preceding 
example^ is^ that trees are combustible. The 
major premise^ namely, every vegetable is com- 
bustible, is first assumed on the ground of ex- 
perience and observation. The minor premise 
barely asserts the fact, that trees belong to the 
class of vegetables. Now if it be certain, that 
combustion belongs universally to vegetables, 
and that trees are included in that class of 
things, it must of necessity follow, that every 



124 ItlEGULAR SYLLOGISMS. 

tree is combustible ; for it is a primary law of 
syllogistick reasonings that vjhatever 7nay be 
affirmed of any general term^ may he affirmed 
of every species and individual^ included within 
its extension. 

165. In the regular syllogism^ each step of 
the reasoning process is distinctly expressed ; 
but in familiar language^ one part is frequent- 
ly omitted^ which rnay be readily found by ex- 
amining the grounds;^ on which the judgment 

is formed. Thus^ 

No language is perfect ; 

Because it is a human invention. 
Perfection is here denied of language^ for no 
other assigned reason^ than because it is a hu- 
man invention. But there is a latent propo- 
sition^ which is the real ground of the judg- 
ment^ and must therefore have been distinctly 
contemplated by the mind^ namely^ no human 
invention is perfect. Let this proposition be 
subjoined to the other two^ and the argument 
will read thus ; 

No language is perfect ; 

Because it is a human invention ; 

And no human invention is perfect. 
This is the regular syllogism reversed j which, 
rectified^ will read thus ; 



REGULAR SYLLOGISMS* 125 

No human invention is perfect ; 
Every language is a liuman invention ; 
Therefore no language is perfect. 

166. Every assertion^ accompanied by a 
reason why it is made^ contains the elements 
of a syllogism^ namely^ the major^ minor^ and 
middle terms. Every such assertion^ made in 
the familiar form of language^ may be trans- 
ferred to a regular syllogism^ by observing the 
following rule. First^ distinguish the reason^ 
on which the attribute of the given proposition 
is affirmed^ or denied of its subject^ and this 
will be the middle term of the syllogism. Let 
this be taken;, in its most enlarged sense^ for 
the subject of a proposition^ to which^ for a 
predicate, unite the attribute of the asserted 
proposition^ and the major premise will be 
formed. Next, to form the minor premise^ we 
have only to predicate the middle term^ already 
found, of the subject of the asserted proposition. 
The original pjroposition^ without the reason^ 
before annexed to it; will constitute the conclu- 
sion of the svlloQ;ism. 

167. For example. Dr. Johnson says of en- 
vy. '* It is; above all other vices, inconsistent 

^Svith the character of a social being, because 

11^ 



126 REGULAR SYLLOGISMS. 

" it sacrifices truth and kindness to very weak 
^' temptations/^ Sacrifices truth and kindness to 
very weak temptations is the reason^ why envy 
is pronounced^ above all other vices^ inconsis- 
tent with the character of a social being. This 
then must form the middle term of the syllo- 
gism. But as this collection of words repre- 
sents an attribute^ and not a person or thing 
really existing^ it cannot be enlarged^ so as to 
become the subject of a general proposition^ by 
simply placing before it one of the common 
signs of universality^ all^ every ^ or each; it 
must be preceded by some universal sign of 
a different sort^ as xvhatever^ that ivhichy or 
the like. Thus ; 

That, which sacrifices truth and kindness to very 
weak temptations, is, above all other vices, inconsistent 
with the character of a social being ; 

Envij sacrifices truth and kindness to very weak temp- 
tations ; 

Therefore envy is, above all other vices, inconsistent 
with the character of a social being. 

In this maimer may the simple elements of 
reasonings however obscured^ in any instance^ 
by rhetorical language^ or complicated forms 
of speech, be easily collected, and exhibited in 
a regular syllogism. 



REGULAR SYLLOGISMS. 127 

168. As the major proposition of a syllogism 
must always be universal^ the middle term^ as 
the subject of this pro ^osition^ must be taken 
in a universal sense. Every middle term must 
represent either some class of persons or things^ 
or else some attribute common to a whole class 
of beings. If the middle term denote persons 
or things,, something must be asserted hypo- 
thetically^ in the major proposition^ to agree 
with^ or to be repugnant to that whole class of 
beings ; and in this class the minor term must 
be included ; which it is the sole business of 
the minor proposition to affirm. In the conclu- 
sion^ we apply to the minor term^ separately^ 
the same predicate^ which was applied to it in 
the major proposition^ in connexion with the 
whole class of things^ to which it belongs. 

169. If the middle term express an attri- 
bute^ it must be asserted in the major propo- 
sition^ that^ to whatever person or thing the 
attribute^ forming the middle term^ can be as- 
cribed^ the major term may be ascribed also* 
In the minor proposition^ the attribute^ which 
forms the middle term^ is declared applicable 
to the minor term. In the conclusion^ the a- 
greement or repugnancy^ which was before ad- 



128 REGULAR SYLLOGISMS. 

mitted between the middle and major terms^ 
must be also admitted between the major and 
minor terms. 

170. Any regular syllogism may be reduced 
to the familiar form of reasonings by the follow- 
ing rule. First; state the conclusion^ omitting 
the illative^ therefore ; then^ subjoin the middle 
term together with the minor^ or some pronoun 
as its substitute^ preceded by some causal 
particle; as since^ for^ or because. For exam- 
ple; 

Every animal, possessing wings and feathers, is a bird ; 
An ostrich is an animal, possessing wings and feathers ; 
Therefore an ostrich is a bird. 

This syllogism may be thus expressed in the 
familiar form of reasoning ; 

An ostrich is a bird ; 

Because it has wings and feathers. 

171. Each of the preceding syllogisms con- 
cludes with a universal proposition. The con- 
clusions of the four following examples are of 
different kinds. 

I. 

Whoever disregards the rights of his fellow beings, 

deserves the detestation of mankind ; 
Tyrants disregard the rights of their fellow beings ; 
Therefore tyrants deserve the detestation of mankind. 



REGULAR SYLLOGISMS. 129 

II. 

They, who subvert the foundations of morality and 
religion, ought not to be respected 5 

Atheists subvert the foundations of morality and 
religion ; 

Therefore atheists ought not to be respected. 

III. 

Every creature, which can live in more elements than 

one, is amphibious ; 
Some animals can live in more elements than one; 
Therefore some animals are amphibious. 

IV. 

No person of dissolute habits can be a safe companion ; 
Some persons of improved minds are dissolute in their 

habits ; 
Therefore some persons of improved minds are not 

safe companions. 

The conclusion of the first syllogism is a 
universal affirmative proposition ; that of the 
second^ a universal negative 5 that of a third^ 
a particular affirmative ; and that of the fourth, 
a particular negative. These are all the kinds, 
into which propositions are distinguished, in 
reference to quantity and quality.^ 

^ Common systems of logick. Collard, Logick, part IV. ch. 4, 5, 



130 IRREGULAR SYLLOGISMS. 

CHAPTER ELEVENTH. 

ENTHYMEMES, 

172. Besides the regular^ categorical syllo- 
gism^ described in the preceding chapter^ tliere 
are some other kinds of single syllogisms^ which 
have different degrees of irregularity in their 
construction. Among these may be placed the 
enthymeme^ which is an abridged;, or defective 
syllogism^ consisting of the conclusion and on- 
ly one of the premises ; the other being sup- 
pressedj as too obvious to need insertion. It 
is of very general use^ both in writing and con- 
versation. 

173. Which of the premises is omitted in 
any instance may be known^ by the following 
rule. If the subject of the conclusion be ex- 
pressed in the given premise^ or proposition^ con- 
taining the reason^ the major premise is omit- 
ted ; if the predicate of the conclusion be ex- 
pressed^ the minor premise is wanting. Thus^ 

Whatever tends to subvert the civil government, should 

be deprecated ; 
Therefore civil dissensions should be deprecated. 

Christianity teaches the way to future happiness ; 
Therefore It should be diligently sought. 



IRREGULAR SYLLOGISMS. 131 

The minor premise is omitted in the first ex- 
ample^ and the major in the second. Let these 
be supplied^ and the syllogisms will be complete. 

Whatever tends to subvert the civil government should 

be deprecated ; 
Civil dissensions tend to subvert the civil government ; 
Therefore civil dissensions should be deprecated. 

That knowledge, which teaches the way to future happi- 
ness, should be diligently sought ; 
Christianity teaches the way to future happiness ; 
Therefore Christianity should be diligently sought. 

174. Enthymemes may be expressed in va- 
rious ways^ and have sometimes been distin- 
guished into several kinds. Those are the 
most regular^ which conform to the syllogistick 
order. In these the conclusion is placed after 
the proposition, which contains the proof, and^ 
by supplying the omitted proposition, the syl- 
logism is rendered perfect, without any other 
alteration. But, in familiar conversation, it is 
more common to express the conclusion first, 
and then to subjoin the reason, on which it is 
grounded, preceded by a causal particle. As^ 

Enthusiasm should be avoided ; 
Because it leads us astrav from reason. 



132 IRREGULAR SYLLOexISMS. 

They, who deny a future state of retribution, are in 

error ; 
For tliey deny the doctrine of the bible. 

175. Although the conclusion be placed af- 
ter the reasoning proposition^ still the enthy- 
meme will not be regular^ unless the syllogis- 
tick language and arrangement be employed. 
The following sentence is an enthymeme of this 
sort; 

" Since it is the understanding, that sets men above the 
"rest of sensible beings, and gives him all the ad- 
" vantage and dominion, which he has over them ; 

" Jif: is certainly a subject, even for its nobleness, worth 
" our labor to inquire into.'^* 

Each of these enthymemes contains the ele- 
ments of a syllogism^ namely^ the major, minor^r 
and middle terms ; which may be easily distin- 
guished. The suppressed propositions are 
readily supplied by the mind ; and the omis- 
sion of them contributes to the brevity and 
elegance of language. 

176. An act of reasoning may be stated 
hypothetically ; thus, 

The African slave-trade should be discountenanced ; 
ijf 1^ be a violation of i\iQ natural rights of man. 

^ Locke^ Essay, Introduction. 



IRREGULAR SYLLOGISMS* 133 

Here the predicate^ discountenanced^ is not 
applied to the African slave-trade absolutely ; 
but only on condition of its being a violation of 
man's natural liberty. Still the reasoning is 
the same^ as if it were expressed in this abso- 
lute form ; 

The African slave-trade is a violation of the natural 

rights of man ; 
Therefore it should be discountenanced by all. 

The judgment is formed in the two cases by a 
comparison of precisely the same things, 

177. What are here considered^, as familiar 
enthymemes^ have usually been received^ as 
compound propositions^ and have been distrib- 
uted into different species^ under the heads of 
causal^ discretive^ and conditional, But^ that 
they cannot justly be regarded^ as mere prop- 
ositions of any sort^ is evident from this^ that 
each example contains two entire propositions. 
[See No. 80.] It is equally manifest^, that 
they represent complete acts of reasonings since 
in each the elements of a perfect syllogism are 
expressed.^ 

^ Collard, Logick, part IV. ch. 6. 
12 



134 IRREGULAR SYLLOGISMS, 

CHAPTER TWELFTH. 

CONDITIONAL AND DISJUNCTIVE SYLLOGISMS. 

178. ^ conditional^ or hypothetical syllogism 
is one^ whose major proposition is conditional. 
Thus^ 

If men have vicious propensities, they need the restraints 

of government; 
But men have vicious propensities ; 
Therefore they need the restraints of government. 

The major premise consists of two entire prop- 
ositions^ which make an enthymeme. The 
minor premise and the conclusion constitute 
another enthymeme^ expressing the same mean- 
ing as the other^ with only this difference^ that 
what is stated hypothetically in the firsts is 
expressed absolutely in the last. The first 
part of the major, containing the condition, is 
called the antecedent ; and the last, which con- 
tains the conclusion, the consequent. If the 
antecedent be admitted in the minor premise, 
the consequent must be admitted in the conclu- 
sion ; for the condition, stated in the antece- 
dent, must always be such, as necessarily to re- 
quire the truth of the consequent. By the 
same necessity it will follow, that, if the conse- 



IRREGULAR SYLLOGISMS. 135 

querit be contradicted in the minor^ the ante- 
cedent must be contradicted in the conclusion. 
Thus, 

If death be an eternal sleep, the scriptures are not true ; 

But the scriptures are true ; 

Therefore death is not an eternal sleep. 

179. In conditional syllogisms then there are 
two ways of reasoning, which lead to certain 
conclusions. The first is called arguing from 
the position of the antecedent to the position 
of the consequent; and the other, arguing from 
the removal of the consequent to the removal 
of the antecedent. These are the only modes 
of true reasoning in this sort of syllogism, for 
we are not at liberty to adopt the contrary 
course, and argue from the admission of the 
consequent to the admission of the antecedent ; 
nor from the removal of the antecedent to the 
removal of the consequent. This will be man- 
ifest in the following example. 

If W. were a general, he would have power; 
But W. is not a general ; 
Therefore he has not power. 

If W. be a general, he must be obeyed ; 
But W. must be obeyed ; 
Therefore he is a general. 



136 IRREGULAR SYLLOGISMS, 



[ai^j' 



The falsehood of the consequent will not fol- 
low from the falsehood of the antecedent ; nor 
the truth of the antecedent^ from the truth of 
the consequent. The one may be true^ and 
the other may be false for different reasons 
from those;, which are assigned. 

180. ^ disjunctive syllogism is one^ whose 
major premise is disjunctive. Thus^ 

The world is either self-existent, or the work of some 

finite, or of some infinite being ; 
But it is not self-existent, nor the work of any finite 

being; 
Therefore it is the work of an infinite Being. 

The business of the major proposition of this 
syllogism appears to be^, to enumerate several 
predicates^ of which one only can belong to the 
subject. If then the minor establishes one of 
these predicates^ the conclusion must remove 
all the rest ; or if^ in the minor premise^, all the 
predicates but one are removed^, the conclusion 
must establish that^ which remains. This pro- 
cedure has been denominated arguing from the 
assertion of one to the rejection of the rest ; 
or^ from the denial of one^ two^ or more^ to the 
establishment of the remainder. But the term^ 
arguing^ is applied to it without any good rea- 



COMPOUND SYLLOGISMS. ISf 

son ; since it is nothing more^ than a formal 
and circuitous method of stating a fact. 

CHAPTER THIRTEENTH. 

COMPOUND SYLLOGISMS. 

181. A compound syllogism consists of more 
than three propositions ; and may he resolved 
into two or more syllogisms. Of these the prin- 
cipal kinds are the Epichirema^ Dilemma^ and 
Sorites. 

The Epichirema is a compound argument^ 
of which the major and minor premises are sep- 
arately proved^ before the conclusion is drawn. 
Example. 

Unjust laws endanger the stability of government ; for 
they create discontent among the people ; 

Laws, which restrain the freedom of conscience, are un- 
just ; for they require people to abandon their dear- 
est concerns ; 

Therefore laws, which restrain the freedom of conscience, 
endanger the stability of government. 

The major and minor premises^ v^ith their 
respective proofs^ form two enthymemes^ which 
may readily be reduced to regular syllogisms^ 
Discard these proofs^ and a regular syllogism 
will remain. 



13S COMPOUND SYLLOGISMS. 

182. The epichirema is much used in con- 
versation^ puhlick harangues^ and oratorical 
discourses. Cicero^s defence of Milo is an argu- 
ment of this sort. His first position is^ that it 
is lawful for one man to kill another^ who lies 
in wait to kill him. This he proves from the 
laws of nature and the customs of mankind. 
His second position is^ that Clodius lay in wait 
for Milo^ with a murderous intent ; which he 
proves by his equipage^ arms^ guards^ and other 
circumstances. Then he infers the conclusion^ 
namely^, that it was lawful for Milo to kill 
Clodius* 

183. The Dilemma"^ is a compound argument^ 
which establishes a general conclusion^ either 
directly by proving its necessity ^ or indirectly 
by showing the impossibility or absurdity of 
its contrary^ in every supposeable case. Thus^ 

Every magistrate must either execute the laws, or suffer 

them to be violated ; 
if he execute them, he will be hated by the vicious and 

profligate; 
If he suffer them to be violated, he will be hated by the 

wise and virtuous ; 
Therefore, every magistrate is exposed to hatred from his 

fellow men. 

* A/5, his^ and ><cci^<^au^ capiiP, 



COMPOUND SYLLOGISMS. 139 

The subject of the conclusion is first divided 
into two classes, namely, those magistrates, 
who do, and those, who do not execute the 
laws* The attribute, hatred^ is then affirmed 
of each class separately, and is finally predi- 
cated of the whole subject. This dilemma 
may be res9lved into three regular syllogisms. 
The major premise and the conclusion, taken 
together, constitute a regular enthymeme ; and 
the four intervening propositions form two 
enthymemes ; hypothetically stated. 

184. Pyrrho, the ancient sceptic, asserted, 
that no one can have certain knowledge of any 
tiling. One of his friends reproved him in the 
following dilemma. 

You either know what you say to be true, or you do not 

know it ; 
If you do know it to be true, that very knowledge proves 

your assertion to be false, and you do wrong to 

make it ; 
If you do not know it to be true, you do wrong to assert 

it, since no one has a right to assert what he does 

not know to be true ; 
Therefore, in either case, you do wrong to assert that no 

one can have certain knowledge of any thing. 

185. A dilemma is a form of argument 
frequently employed both in moral and math- 



140 COMPOUND SYLLOGISMS. 

ematica] reasoning. The geometrician adopts 
this method^ whe% in order to prove the 
equality of two lines or angles^ he first assumes^ 
that, if they are not equal^ one must be either 
greater or less than the other ; and, having re- 
moved both these suppositions, he thence infers, 
that the proposed lines or angles are equal. 

186. In order to understand fully the prin- 
ciple of reasoning in a dilemma, it is necessary 
to consider the major premise as conditional^ 
the first part of which is commonly omitted, to 
wit, the antecedent, which consists of a general 
assertion, conditionally made, which it is the 
object of the dilemma to disprove. What 
usually appears, as the major premise, is only 
the consequent of this member, consisting of an 
enumeration of all the suppositions, of which 
the subject will admit. If then all these sup- 
positions be rejected in the minor premise, the 
antecedent will of necessity be rejected in the 
conclusion. This reasoning proceeds univer- 
sally from the removal of the consequent to the 
removal of the antecedent. 

1S7. A dilemma may be defective in two 
ways; first, when the eoiKlitioos are not ac- 
curately stated in the mdjor premise ; secondly, 



COMPOUND SYLLOGISMS. 141 

when the argument may be retorted with equal 
force on him^ who offers it. A remarkable 
instance of the retort of a dilemma happened 
in the singular controversy between Protagoras 
and Euathlus. The former engaged to teach 
the latter the art of pleading for a stipulated 
reward^ one moiety of which was to be paid 
in hand^ and the other when the pupil gained 
his first cause at court. After a short time 
Protagoras sued Euathlus for the remaining 
moiety of the money^ and made use of this 
dilemma ; 

The cause must be decided either in my favour, or in 
yours; 

If it is decided in my favour, the sum will be due to me 
according to the sentence of the judge : 

If it is decided in jour favour, it will be due to me by' 
virtue of our contract ; 

Therefore whether I gain or lose the cause, I shall ob- 
tain the reward. 

Euathlus thus retorted the dilemma ; 

I shall either gain the cause, or lose it ; 

If I gain the cause, nothing will be due to you according 

to the sentence of the judge ; 
If I lose the cause, nothing will be due to you according 

to our contract ; 
Therefore in neither case shall I pay you the reward. 



142 COMPOUND SYLLOGISMS. 

Sometimes the consequent of the major consists 
of more than two parts, and then the syllogism 
is called a trilemma^ tesseralemma^ or the like. 
188. The Sorites^ is an irregular ^ cojnpound 
argument J consisting of a series of propositions^ 
arranged in such a manner j that the predicate 
of each preceding proposition forms the subject 
of that ^ which follows ; and the concluding "prop- 
osition unites its predicate to the subject of the 
first. Thus^ 

Avaricious men have many desires ; 
They, who have many desires, are in want of many things ; 
They, who are in want of many things, are unhappy ; 
Therefore avaricious men are unhappy. 

This example contains the substance of two 
syllogisms; which may be thus stated in regu- 
lar form ; 

I. 

Those, who have many desires, are in want of many things ; 

Avaricious men have many desires ; 

Therefore avaricious men are in want of many things. 

II. 

Those, who want many things, are unhappy ; 
Avaricious m.en want many things ; 
Therefore avaricious men are unhappy. 

■^ Siy^o$, congeries, acervus* 



eOMPOUNB SYLLOGISMS. 143 

189. Every sorites may be resolved into as 
many syllogisms^ as it contains middle terms; 
or, as it has propositions intervening between 
the first and the last. The second proposition 
of the sorites forms the major premise of the 
first syllogism ; the third^ the major of the 
second, and so on. The following example 
may be reduced to four syllogisms. 

The mind is a thinking substance; 

A thinking substance is a spirit ; 

A spirit has no composition of parts ; 

That, which has no composition of parts, is indissohible j 

That, which is indissoluble, is immortal ; 

Therefore the mind is immortal. 

190. A sorites may be formed of hvpothetic- 
al enthymemes, any number of which may be 
so joined in a series^ that the consequent of 
each shall become the antecedent of the next 
following ; in which case, by establishing the 
antecedent of the first, we establish the conse- 
quent of the last ; or, by removing the conse- 
quent of the last, we remove the antecedent of 
the first. This is manifest in the follovdag 
example. 

If men are to be punished in another world, God must 

be the punishtr ; 
If God be the punisher, the punishment must be just ; 



T, 

144 SOPHISMS. 

If the punishment be just, the punished must be guilty ; 
If the punished be guilty, they could have done otherwise ; 
If they could have done otherwise, they were free agents ; 
Therefore, if men are liable to punishment in another 
world, they must be free.* 

CHAPTER FOURTEENTH. 

SOPHISMS^ 

191. A knowledge of the different kinds of 
reasonings with their respective laws and 
principles^ is of important use in enabling us 
to detect the sophistry and false reasonings 
employed in the support of error. But the 
rules of logick are of little service^ till habit 
has rendered them familiar. By frequently 
examining the judgments and conclusions^ 
which we have formed^ and comparing them 
with those rules of procedure^ which lead to 
certain results^ we insensibly acquire the habit 
of conducting our intellectual processes with 
accuracy^ and also a facility in detecting the 
false deductions of others. 

192. Arguments^ which contain a latent 
fallacy under the general appearance of cor- 

* Common systems of logick. Locke. Essay on the Under- 
standing, B. IV. ch. 17. 



Sophisms. 145 

tectness^ are denominated sophisms. They 
have been distinguished into various kinds, 
from which the following are selected, as those 
which are practised with the greatest frequency 
and success. 

193. First. Ignoratio Elenchi^ a misappre- 
hension of the question. This sophism is com- 
mitted, when the arguments employed are of 
a nature to establish some other point, foreign 
to the question in debate ; as if a person should 
attempt to prove, that Alfred the Great was a 
scholar, by affirming only, that he founded the 
University of Oxford ; or, that Peter the Her- 
mit was not a Christian, by proving that he 
w^as an ignorant fana^tick. Neither of these 
facts has any necessary connexion with the 
question to be proved ; for a man may be a 
patron of science, without being learned him- 
self ; and an ignorant fanatick may be a be- 
liever in Christianity. 

194. Disputants are frequently guilty of this 

fallacy, when, in the heat of controversy, they 

wander insensibly from the precise subject of 

discussion. It is also sometimes committed by 

design ; as when a disputant, finding his 

adversary too powerful, or his position untena- 

13 






146 SOPHISMS. 

ble^ endeavours to gain an advantage^ by 
altering the question. The only effectual 
security against this species of sophistry is^ to 
have the subject accurately defined^ and to 
keep it steadily in view. 

195. Secondly. Petifio Principiiy a begging 
of the question. This consists in offerings as 
proof of a proposition^ the substance of that 
proposition in other words. Thus a person 
attempts to prove^ that God is eternal, by as- 
serting ll^at his existence is without beginning 
and without end. The proof and the question 
to be proved are substantially the same. This 
fallacy is often practised in familiar conversa- 
tion. Thus a person asks^ why opium induces 
sleep ? He is answered^ because it possesses 
a soporifick quality ; which is equivalent to 
sayings that it induces sleep^ because it indu- 
ces sleep. So we are told^ that the grass 
grow s^ by means of its vegetative power ; and 
that bodies tend to the centre^ by reason of 
their gravitation. 

196. Thirdly. Argiiing in a circle. This is 
a kind of sophistry nearly related to the pre- 
ceding ; and consists in making two propositions 
reciprocally prove each other, Thus^ the 



SOPHISMS. 147 

Papists prove the truth of the scriptures^ by 
the infallible testimony of the church ; and 
then establish the infallibility of the churchy 
by the authority of the scriptures. The Ne- 
cessarians practise this sophistry, when they 
bring their hypothesis to prove a fact^ and 
then allege the fact^ as proof of their hypoth- 
esis. They first assume^ gratuitously^ that the 
mind acts mechanically, like the body ; and 
that it never can act^ unless the motive^ which 
causes the action^ be greater than any other^ 
then existing in the mind. Any particular vo- 
lition is then declared to be necessary^ because 
the motive^ which produced it, was the strong- 
est then in the mind. But when asked for the 
proof^ that this motive was the strongest, they 
simply refer us to the volition, which otherwise 
could not have taken place. That is^, the 
volition was necessary ^ because it was produced 
by the strongest motive ; and the motive must 
have been the strongest^ because the volition 
was produced. 

197. Fourthly. J\^on causa pro causa ; or 
the assignation of a false cause. From an un- 
willingness to be thought ignorant, people often 
impose on themselves, and on the credulity of 



148 SOPHISMS. 

their fellow men^ by assigning, as the cause of 
an event^ something, that has no perceivable 
connexion with it. Among illiterate people, 
rare occurrences are sometimes thought to have 
a connexion, barely on account of their proxim- 
ity in time or place* Thus, should the ap- 
pearance of a comet be followed by a famine, 
pestilence, or any other grievous calamity, 
many people would consider the comet, as the 
cause of that calamity. So if a person have 
committed any flagrant crime, and shortly 
after meet with some distressing evil, the for- 
mer is readily believed to have been the cause 
of the latter. This sophism is practised by all 
those impostors, who make pretensions to some 
supernatural skill in interpreting enigmatical 
circumstances, and in presaging future events 
from dreams and other omens ; by which means 
they flatter the superstition and credulity of 
mankind. 

198. Fifthly. Another species of sophistry 
is called fallacia accidentis. This consists in 
pronouncing concerning the general nature or 
properties of a thing, from some accidental cir- 
cumstance. As, when certain amusements are 
c6iidemnei3, as universally unlawful, because 



METHOD. 149 

they are occasionallj^ carried to excess. So 
religion has been denounced;, as an evil to 
mankind, because it has sometimes been as- 
sumed, as a cover for crimes. If a medicine 
have operated unfavourably, weak persons are 
ready to reject it universally; or, if its good 
effects have been extraordinary, they are ready 
to adopt it in all cases whatsoever. This is the 
great cause of error, the substitution of local, 
partial, temporary connexions, for universal 
and unchangeable. The great remedy of 
error is the extensive observation and com- 
parison of particulars, or laborious induction ; 
and this is the true logick. 

CHAPTER FIFTEENTH. 

DISPOSITION OR METHOD. 

199. Method, in logick, is a proper classifi- 
cation and arrangement of our thoughts on any 
subject, either to facilitate the discovery of new 
truths, or to assist us in communicating to oth- 
ers truths, already known ; or, lastly, to ena- 
ble us to preserve for future use the knowledge, 
which we have acquired. The disposition best 
adapted to the investigation of truth is the 

13^ 



150 METHODS 

analitick method ; which is therefore denomi-- 
nated the method of invention ; and that which 
is best suited to the communication of knowl- 
edge/ i^ the synthetick method^ which for this 
reason has been called the method of instruc- 
tion. In both of these methods, ideas are ar- 
ranged in such order, as to exhibit their mu- 
tual connexions and relations. 

200. Analysis'^ signifies an operation^ by 
tuhich some process of art is retraced^ or some 
compound subject is reduced to its elementary 
parts. Synthesis\ implies the act of collecting 
or putting together. By the first we begin 
with the whole, and proceed by successive steps 
to the parts, of which it is composed ; by the 
last we begin with the parts, or the most gene- 
ral principles, and proceed by combining them 
in due order to make up the whole. 

201. Analysis and synthesis are terms of fre- 
quent use in many sciences, but they have not 
invariably the same signification annexed to 
them. They always however denote opposite 
processes, one beginning where the other ter- 
minates ; and they reciprocally explain each 
other. They may be sometimes both employ- 

^ MolXv(^^ resolmh t ^v^uenf^t, conjungo^ compono. 



METHOD. 151 

ed with equal advantage in explaining the 
same thing. Thus^ the mechanism of a com- 
plicated machine may be shown by either meth- 
od. We may do it analytically, by taking the 
machine, in its entire state, and separating its 
parts in the reverse order of their combination^ 
carefully explaining each part as we proceed 
till we arrive at that, with which the mechan- 
ical construction commenced. Or we may adopt 
the synthetick method, and, beginning with the 
^ parts, in a state of separation, place them suc^ 
cessively in their former order, till the combi- 
nation is restored. 

202. Most of the improvements in the dif- 
ferent sciences and arts have been made by a- 
nalysis. It is by this method, that things have 
been ranked into classes. A species is formed 
by analysing individuals ; and a genus, by ana- 
lysing species. We practise the same meth- 
od in learning to read the language of our 
country. We first acquaint ourselves with the 
letters of the alphabet. We next trace out their 
powers, by observing in what manner they are 
sounded, as they are variously combined in 
syllables and words. In this way we at length 
acquire some general rules; by which we can 



15i^ METHOD. - 

riba^dily give to each letter its appropriate 
sound, in any new combination. By the same 
method we learn a foreign language, and uni- 
versal grammar ; also the philosophy of mind^ 
anatomy, chemistry, botany, and other branch- 
es of natural knowledge. 

203. The synthetick method is not adapted 
to the investigation of new truths, and is rarely 
employed for that purpose. It is a process of 
composition ; and consists in putting together 
a number of things in a particular manner, so 
aiatd 'Accomplish some end proposed. But Irf' 
order to do this, it is necessary for a person 
previously to possess the knowledge, which it 
is the object of the operation to evince. With- 
out this knowledge, he would have nothing to 
guide him in the selection or arrangement of the 
parts ; and would be in the condition of a man, 
who should undertake to make some very com- 
pound medicine, without knowing the ingredi- 
ents, of which it is composed. By successively 
mixing substances of different kinds, and in 
various proportions, directed only by casual 
circumstances or mere conjecture, it is possi- 
ble for him ultimately to succeed ; but this 
w'ould not be likely to happen, till after 



METHOD. 153 

much waste of time^ and many unsuccessful 
efforts. 

204. The superiority of the analytick over 
the synthetick method^ in the investigation of 
new truths^ is very forcibly shewn by Mr. 
Stewartj, in the following example. " Suppose 
*' a knot^ of a very artificial construction^ to be 
^^put into my hands^, as an exercise for my 
" ingenuity ; and that I was required to inves- 
" tigate a rule, which others, as well as myself^ 
•^ might be able to follow in practice, for mak- 
'' ing knots of the same sort. If I were to 
" proceed in this attempt according to the 
'' spirit of a geometrical synthesis^ I should 
'' have to try, one after another, all the vari- 
*' ous experiments, which my fancy could de- 
'' vise, till I had at last hit upon the particular 
" knot, I was anxious to tie. Such a process^ 
" however, would evidently be so completely 
" tentative, and its final success would after all be 
^^so extremely doubtful, that common sense 
" could not fail to suggest immediately the idea 
" of tracing the knot through all the various 
^^complications of its progress, by cautiously 
"undoing or unknitting e^ioh successive turn 
^* of the thread, in a retrograde order, from the 



164 METHOD. 

^^ last to the first. After gaining this first step^ 
^^were all the former complications restored 
^^again^ by an inverse repetition of the same 
" operations^ which I had performed in undoing 
" them^ an infallible rule would be obtained for 
•^^ solving the problem^ originally proposed.'^* 

205. Though knowledge is chiefly acquired 
by the analytick method^ it is most convenient- 
ly conveyed to others by the synthetick. The 
teacher uses one method^ while the pupil 
practises the other. The synthetick method 
is the most plain^ concise^ and regular. It 
coincides with the order, in which the useful 
arts are practised, and most of the business 
of life is transacted. It begins with the most 
general and obvious principles, and leads the 
mind directly from known truths, to those 
which are unknown. Instruction in every 
science is given synthetically. It consists in 
precribing rules more or less general ; and 
these rules are nothing more, than the results 
of analytical processes, previously performed. 

206. The other purpose of method is to se- 
cure to the mind a command over the knowl- 
edge, it has acquired. Memory includes the 

'' Elem. of the Phil, of the Mind, vol. 2, ch. 4, sect. 3,. 



METHOD. 155 

power of treasuring up and preserving ideas ; 
and also that of recalling them^ when we have 
occasions for applying them to use. The lat- 
ter power is usually termed recollection ^ In 
respect of both these faculties, the burden of 
memory is diminished by arranging the sub- 
jects of our knowledge under distinct heads, 
and charging the memory with some leading 
objects only, in each class. But the same form 
oj arrangement will not equally contribute to 
render the memory retentive and ready. ^ 
For this reason, no plan can be prescribed, 
which will be equally beneficial to all. 

207. People, engaged in the active business 
of life, are under the necessity of carrying in 
their minds a multitude of particulars, which 
are of no further use, than to assist them in the 
daily business of their calling. To such per- 
sons a prompt recollection is of the highest im- 
portance, as it contributes to the despatch of 
business. Thev will therefore seek an ar- 
rangement, with reference to this object ; and 
the surest method of effecting it is an arbitrary 
one, suggested by the circumstances of their 
situation, all which are of a local and tempo- 

* Stewart, Elem. vol. 1, ch. 6, sect. 2. 



156 METHOD. 

rary nature. While they continue their ha- 
bitual pursuits, their thoughts will be succes- 
sively called up by the objects^ offered to their 
senses ; but on changing their situation^ so as 
to lose their familiarity with those objects, the 
ideasj which were associated with them, must 
in a short time be irretrievably lost. 

208. A different method of arrangement is 
necessary^ to give the mind a durable posses- 
sion of the acquisitions^ it has made. The on- 
ly arrangement^ capable of effecting this pur- 
pose^ is that^ which refers the truths^ we are 
solicitous to preserve, to the general principles, 
with which they are connected. By having 
our ideas distributed according to this method, 
reason can lend its aid to the powers of memo- 
ry, by tracing the natural relations and con- 
nexions of things, and thus deducing one truth 
from another. Some sort of arrangement or 
other is indispensable to persons of every con- 
dition ; otherwise but a small proportion of 
the thoughts, which pass through the mind, 
pQuld by any effort be recalled. 



RULES OF CONTROVERSY. 157 

RULES OF CONTROVERSY. 

209. From the limited extent of human 
knowledge, and the different points of view, in 

I which the same subjects may be contemplated 
by different minds, it follows of necessity, that 
a diversity of opinions must be entertained on 

\ many subjects of speculation. In whatever 
manner people are first led to form their opin- 
ions, they are usually disposed to defend them 
afterwards with zeal and pertinacity. Hence 
arise controversies and disputes, which are 
oftentimes conducted with such intemperate 
and misguided zeal, as to inflame animosities, 
by which the comfort and harmony of society 
are impcdred. 

210. These are the worst fruits of contro- 
versy. They are, however, merely incidental 
effects ; and are counterbalanced by others of 
an opposite character, and of high importance 
to the interests of truth and virtue. The 
advantages of controversy consist in having 
questions of difficulty and moment settled in a 
satisfactory manner. The principles of gov- 
ern m.ent and law have been immovably fixed 

14 



158 RULES OF CONTilOVERSY. 

by the debates^ v/hich have passed in deliber- 
ative assemblies and in courts of justice. 

211. All questions^ not susceptible of rigor- 
ous demonstration^ can be correctly settled 
only by a full and impartial comparison of the 
reasons on both sides. This is seldom done^ 
with sufficient exactness^ by the solitary inves- 
tigation of an individual. Men rarely enter 
on the examination of a question wholly free 
from the bias of a previous opinion respecting 
it^ which makes them more solicitous to find 
arguments for one side than for the other. 
It is only when the talents of different persons 
are enlisted^, and opposite opinions are contend- 
ed for^ that questions are traced in all their 
bearings^ and the grounds of an equitable 
decision are fully exhibited. 

212. The importance of controversy may be 
inferred from the use^ which has been made of 
itj in every period of the world. It has been 
adopted^ as the principal mode of transacting 
business^ in the halls of legislation and in courts 
of justice^ where questions of the deepest con- 
cern to individuals and communities are decid- 
ed. The minds of youth have been trained 
to it in seminaries of education^ where the 



RULES OF CONTROVERSY. 159 

practice of disputation, in various forms, has 
been preserved, as a salutary discipline of the 
mental powers. 

213. As controversy, especially when carri- 
ed on from motives of victory or reputation^ 
is liable to be productive of evil rather than of 
good, it is incumbent on all, who engage in it, 
from whatever motives, to observe rigorously 
those laws and principles, by which the former 
may be avoided and the latter secured. The 
following rules, sometimes called canons of 
controversy, have been highly approved by 
writers of learning and discernment.'"^ 

214. Rule. 1st. 77?^ terms^ in xvhich the ques- 
tion in debate is expressed^ and the precise point 
at issue^ should he so clearly defined^ that 
there could he no misunderstanding respecting 
them. If this be not done, the dispute is liable 
to be, in a great degree, verbal. Arguments 
W'ill be misapplied, and the controversy pro- 
tracted, because the parties engaged in it have 
different apprehensions of the question. 

215. Rule 2d. The parties should mutucdly 

•■ These rules are taken, with slight alterations, from the lectures 
of Dr. Hey, Norrisian Professor in the University in Cambridge. 
They may also be found in Kirwan's logick, vol. 2. 



160 RULES OF CONTROYERSY. 

y '*■ ^' * ^;^ '*.^ 

consider each other ^ as standing on a footing of 
equality in respect to the subject in debate. 
Each should regard the other as possessing 
equal talents^ knowledge^ and desire for truth^ 
with himself; and that it is possible therefore^ 
that he may be in the wrongs and his adversary 
in the right. In the heat of controversy^ men 
are apt to forget the numberless sources 
of error^ which exist in every controverted 
subject^ especially oi theology and metaphysicks^ 
Hence arise presumption^ confidence^ and ar- 
rogant language ; all which obstruct the dis- 
covery of truth. 

216. Rule 3d. All expressions^ which are 
unmeaning^ or without effect in regard to the 
subject in debate^ should be strictly avoided* 
All expressions may be considered as unmean- 
ing, which contribute nothing to the proof of 
the question ; such as desultory remarks and 
declamatory expressions. To these may be 
added all technical^ ambiguous^ and equivocal 
expressions. These have a tendency to daz- 
zle and bewilder the mind^ and to hinder its 
clear perception of the truth. 

217. Rule 4th. Personal refections on an 
adversary shoidd in no instance h^ in4ul^ed<s 



RULES OF CONTROVEItSY. 161 

Whatever be his private character^ his foibles 
are not to be named nor alluded to^ in a con- 
troversy. Personal reflections are not only 
destitute of effect^, in respect to the question 
in discussion, but they are productive of real 
evil. They obstruct mental improvement^ and 
are prejudicial to public morals. They indi- 
cate in him^ who uses them, a mind hostile to 
the truth ; for they prevent even solid argu- 
ments from receiving the attention, to which 
they are justly entitled. 

218. Rule 5th. JVo one has a right to accuse 
his cidversary of indirect motives. Arguments 
are to be answered, whether he, who offers 
them, be sincere or not, especially as his want 
of sincerity, if real, could not be ascertained. 
To inquire into his motives then is useless. 
To ascribe indirect ones to him is worse than 
useless, it is hurtful. 

219. Rule 6th. The consequences of any doC" 
trine are not to he charged on him^ who maintains 
it J unless he expressly avoxvs them. If an absurd 
consequence be fairly deducible from any doc- 
trine, it is rightly concluded that the doctrine 
itself is false ; but it is not rightly concluded, 

that he, who advances it^ supports the absurd 

14* 



162 ftULBS OF INTEKPRETATION* 

consequnce. The charitable presumption^^ iii 
such a case^ would be, that he had never made 
the deduction ; and that^ if he had made it, he 
would have abandoned the original doctrine. 

220. Rule 7th. As truths and not victory, 
is the professed object of controversy^ what- 
ever proofs may be advanced, on either side, 
should be examined xvith fairness and candor ; 
and any attempt to ensnare an adversary by the 
arts of sophistry, or to lessen the force of his 
reasoning, by zvit, cavilling, or ridicule, is a vio- 
lation of the rules of honourable controversy. 

RULES OF INTERPRETATION. 

221. To ascertain the true meaning of a 
written document is often difficult and embar- 
rassing, even when it is of recent date and in 
our own language ; but the difficulty is greatly 
enhanced, when the writing is in a foreign lan- 
guage, or has descended from ancient times. 

222. The circumstances, which aggravate 
the labor of the interpreter, are numerous, and 
of various kinds. No branch of knowledge is 
entirely exempt from them ; but they exist in 
the greatest degree^ in those sciences^ which 



RULES OF INTERPRETATION. 163 

involve our most important interests^ both 
sacred and civil. For this reason^ principles 
and rules of interpretation have been carefully 
formed for developing the true meaning of the 
sacred scriptures and of legal instruments. 

223. The design of interpretation is to 
ascertain the real intention of the writer ; to 
develop the true meaning of his words^ where 
they are obscure or ambiguous ; and to deter- 
mine what was his design^ where his words do 
it but imperfectly. The following rules are of 
a general character^ and may be employed 
with equal advantage^ in explaining writings of 
every kind. 

224. Rule 1st. The interpreter of a written 
document must have a thorough knowledge of 
the language^ in which it was written. 

225. Rule 2d. He must possess an intimate 
acquaintance with the subject of the writing. 
Many words have different significations in 
different sciences and arts ; and the particular 
meaning they were intended to convey, in any 
instance^ must be agreeable to the nature of 
the subject^ on which they were employed. 

226. Rule 3d. The true interpretation of a writ- 
ing often requires a knowledge of the character 



164 RULES OP INTERPRETATION. 

of its author. His peculiar bent of mind;, his 
temperament^ his vocation^ and especially his 
political or religious tenets^ may have had an 
influence, for which some allowance should be 
made. 

227. Rule 4th. If the writing to be interpreted 
be of ancient date, the interpreter should as* 
certain the genuineness of his text ; whether 
it has descended to him as it came from the 
author, without any corruptions or interpola- 
tions from other hands. 

228. Rule 5th. The interpreter should also be 
well acquainted with the history of the country 
and of the period, in which his author wrote. 
Words have different meanings in different ages ; 
and writers are insensibly influenced by the ex- 
isting fashions, and other circumstances of a 
local and temporary nature. 

229. Rule 6th. The mind of the interpreter 
should be wholly free from all antecedent bias 
in favour of any system, doctrine, or creed, 
which might influence his judgment, in the 
interpretation he is about to make. 

230. Rule 7th. In making the interpretation 
of a document, the subject and predicate of 
each proposition should be carefully distin« 



KULES OF IKTERFRETATION, 165 

guished ; the various sentences and clauses 
should be construed in reference to each 
other ; and the resulting sense of all the parts 
should be connected and consistent. 

231. Rule 8th. Words^ which admit of differ- 
ent senses^ should be taken in their most com- 
mon and obvious meanings unless such a con- 
struction lead to absurd consequences^ or be 
inconsistent with the known intention of the 
writer. 

232. Rule 9th. When any words or expres- 
sions are ambiguous^ and may^ consistently with 
common use^ be taken in different senses^ they 
must be taken in that sense^ which is agreeable 
to the subject, of which the writer was treating, 

233. Rule 10th. Doubtful words and phrases 
must always be construed in such a sense, as 
will make them produce some effect ; and not 
in such a sense as will render them wholly 
nugatory. 

234. Rule 11th. Violations of the rules of 
grammar do not vitiate a writing, in which the 
sense is distinctly expressed. When a pas- 
sage is imperfect, or unintelligible, the inter- 
preter is at liberty to supply such words, aa 
are manifestly necessary to render its sensQ 



166 RULES OF INTERPRETATION. 

complete. But he is not allowed^ in a sim- 
ilar case; to expunge certain words from the 
text; in order to give an intelligible meaning 
to those that remain. 

235. Rule 12th. When there are no special 
reasons for the contrary, words should be con- 
strued in their literal, rather than in their fig- 
urative sense ; relative words should be refer- 
red to the nearest; rather than to a remote 
antecedent ; and words, which are capable of 
being understood in either, should be taken in 
their generic, rather than in their specific sense. 

236. Rule 13th. However general may be 
the words, in which a covenant is expressed, it 
comprehends those things only, on which it 
appears the parties intended to contract, and 
not those, which they had not in view. But 
when the object of the covenant is an univer- 
sality of things, it comprehends all the particu- 
lar things, which compose that universality, 
even those, of which the parties had no 
knowledge. 

237. Rule 14th. Whatever is obscure or 
doubtful in a covenant should be interpreted 
by the intention of the parties. If the inten- 
tion of the parties does not appear from the 



CONCLUDING REMARKS. 167 

words of the covenant^ it should be inferred 
from the existing customs and usages of the 
place, in which it was made. If the words of 
a covenant contradict the well known intention 
of the parties, this intention must be regarded 
rather than the words. ^ 

CONCLUDING REMARKS. 

In the preceding summary, an attempt has 
been made to state and explain those rules of 
intellectual discipline^ which may guide and 
improve the reasoning faculties. As the work 
is intended to be strictly elementary^ general 
principles only have been given^ with such plain 
examples^ as might limit and illustrate their 
meaning. The following remarks are subjoin- 
ed for the use of those^ who may wish to ex- 
tend their inquiries on the subject of logickj 
and to the philosophy of the human mind. 

Dr. Reid^s analysis of Aristotle^s Logick 
contains a brief but comprehensive exposition 
of the syllogistick system. A more full ac- 

* Sarti, Dialect: Instlt. Krrwan, Log'ick, Le Clerc, Ars 
Critlca. Vatlel, Law of Nations. Ruth crfortli, Lectures on Gro- 
tiii3> G.lbert, Law of Evidence. PoUiier on obi ig-at ions. De* 
mat on the civil law. 



168 CONCLUDING REMARKS. 

count of the categories^ together with the vari- 
ous laws of syllogistick reasonings may be 
found in the logical treatises of Burgersdicius 
and of Le Clere. 

Of modern systems of logick^ those of Watts 
and of Duncan have been most approved. A 
more recent and valuable treatise, than either 
of thescj is that of Kirwan. 

It is essential to accurate reasoning to dis- 
tinguish those first principles of human knowl- 
edgCj which must be taken for granted^ from 
those propositions^ which require proof. On 
this subject the treatise of Father Buffier^ en- 
titled First Truths, Beattie^s Essay on Truth^ 
and Condillac on the Origin of Knowledge^ are 
valuable sources of information. 

The Novum Organum of Lord Bacon con- 
tains in a small compass those rules of induc- 
tive logick^ which have been followed with the 
happiest success^ both in physical researches^, 
and in the philosophy of the mind. 

On the subject of moral reasonings important 
information may be derived from Gambier's 
Introduction to Moral Evidence^ and from the 
first book of CampbelPs Philosophy of Rhet- 
crick. 



CONCLUDING remauks. 169 

For the general direction of the mind^ in its 
researches after truth^ rules of a more practi- 
cal nature may be found in Lockers Conduct 
of the Understandings and Watts on the Im- 
provement of the Mind. 

The study of those authors^ who reason 
clearly and accurately^ is one of the best meth- 
ods of improving the reasoning powers. For 
this purpose^ Berkeley on the Principles of 
Human Knowledge^ Wollaston on the Religion 
of Nature^ and Baxter on the Soul^ may be 
read with great advantage. The catalogue 
might easily be extended^ if it were thought 
necessary. It will be concluded by referring 
the student to the metaphysical writings of 
Locke^ Reid^ Stewart;, and Brown. They may 
be consulted with great benefit^ on each of the 
subjects above mentioned ; and may be said 
to comprise in themselves a complete system 
of intellectual philosophy. 

But the student should remember^ that nei- 
ther learning the best rules, nor reading the best 
models, can supersede the necessity of intent 
and continued reflectian. "He should dwell on 
the operations of his own mind, and mark the 

difficulties, which prevent his arriving at clear 

15 



170 CONCLUDING BEMAEKS. 

conclusions ; whether they arise from misappre* 
hension of the subject^ from the ambiguity of 
language^ from weakness in the power of at- 
tention^ or from the biasses of association. He 
will thus insensibly form a logick for himself, 
which^ while it embraces the rules, common to 
all minds, will be peculiarly adapted to the 
improvement of his own* 



in 



NOTES AND ILLUSTRATIONS, 



JVote K^ page 17. 

I have used reflection and consciousness as sjnony- 
mous terms, and they are so used by eminent writers on 
pneumatology. Some however have considered them as 
denoting operations specifically different. Dr. Reid says, 
^* reflection ought to be distinguished from consciousness, 
with which it is too often confounded, even by Mr. Locke. 
AH men are conscious of the operations of their own 
minds, at all times while they are awake, but there are 
few who reflect on them, or make them the objects of 
their thought. Though the mind is conscious of its op- 
erations, it does not attend to them ; its attention is turn- 
ed solely to the external objects, about which those op- 
erations are employed." Essay \ston Intel, Powers, \\\ 
another place he says^ that*' attention to things external 
is properly called observation, and attention to the sub- 
jects of our consciousness, reflection.'' This definition 
of reflection is substantially the same with that of Mr. 
Locke, which I have used. 

The foregoing passage from Dr. Reid points out a dif- 
ference in degree, rather than in kind, between conscious- 
ness and reflection. It is true that the bulk of mankind 



ir£- . NOTES, 

pay very little attention to their mental operations. 
But without some degree of attention, they would have 
310 consciousness of them whatever; and so far as they 
do attend to them, so far, according to Dr. Reid's own 
account, they reHect. 

The only way, by which the phenomena of the mind 
can be investigated, is by attending to its successive 
changes and operations, as they are passing; and this 
reOex act of attention is nothing more than an effort of 
the mind to increase or prolong the consciousness of its 
own acts. Reflection on any operation of the mind 
presupposes the actual existence of that operation. It 
may be examined afterwards by the assistance of mem- 
ory, but this subsequent examination cannot be denom- 
inated reflection, agreeably to the strict sense of that 
word. Are we then to believe that reflection and 
consciousness are tw^o distinct simultaneous efforts; and 
each of them different from the operation, which the 
mind is carrying on at the same time? This would 
oblige us to consider the mind, not as simple, but as a 
complication of different powers or agents, one of which 
may be employed in w atching the operations of another, 
while its own acts are examined by a third. 

Dr. Reid defines reflection, "attention to the subjects 
of our consciousness.'^ By this expression he evidently 
supposes consciousness and the subjects of consciousness 
to be different things. But the mind can be conscious 
only of what passes within itself. Consciousness then^ 
according to him, means the notice, which the mind takes 
©f its own operations. Now as he places reflection m 



NOTES. 173 

attention to the subjects of our consciousness, and it ap- 
pears manifest, that by the subjects of consciousness he 
means nothing else than the operations of the mind, it 
follows, even from his own statement, that these terms 
are but different names for the same thing. 

In common use there seems to be a slight difference 
in the import of these terms. By consciousness is com- 
monly understood barely the mind's notice or percep- 
tion of its own acts and modes of existence. But reflec- 
tion is usually employed to express some degree of vol- 
untary attention to the phenomena of the mind, in order 
to ascertain the laws, by which it is governed. As the 
bulk of mankind have no curiosity for such speculations, 
they have been said rarely, if ever, to reflect. 



JVote 3, page 121. 

Logicians have, from the earliest period denominated 
the predicate of the conclusion the major term, and its 
subject, the minor. The only reason, assigned for 
doing this, is, that the predicate of a proposition has a 
wider extension than the subject. But this is not a 
sufficient reason for calling it the major term, since in all 
our affirmations and negations we are invariably governed 
by the comprehension of terms, without the slightest re- 
gard to their extension. We assert' the more general of 
the less general for this manifest reason, that the former 
is a part of the latter. We predicate the genus of the 
species, but not the species of the genus. The predicate 

15"^ 



174 NOTES. 

of a proposition is only an attribute of the subject; and* 
in this light it must be viewed, in order to render the 
proposition true. When, for example, we affirm that 
saffron is yellow, we refer a single property to a subject, in 
which it is known to coexist with several other proper- 
ties. In doing this, we are guided by our knowledge of 
that plant, without inquiring what other bodies there are 
in existence, which have a yellow color. And we pro- 
ceed in the same way, when the predicate has no greater 
extension than the subject, as vyhen we affirm that iron 
is susceptible of magnetical attraction. 

In passing from one rank of beings to another, in the 
order of their classification^ we observe that each supe- 
rior class stands in the next below it. Thus we may 
say a mastiff is a do<r, a dog is an animal, and an animal 
is a being, that has life, sense, &c. It is obvious that the 
first subject contains each of the predicates that follow. 
As in an act of judgment one thing is perceived to be 
contained in anotlK^r, so, in syllogistic reasoning, one 
proposition is shown to be contained in another, that in 
a third, and so on. This process has been aptly illus- 
trated by a collection of boxes of different sizes, placed 
one in another. In such a nest of boxes, it would be 
natural to say of that which Vv^as placed first, and contain- 
ed ail the rest, that it was the largest box, and of that, 
which was in the centre, and had no other in it, that it was 
the least box. But, in giving names to the three terms 
of a syllogism, this rule of common sense has been viola- 
ted. The less is made to contain the greater. The 
predicate of the conclusion, which is contained in each 



NOTES. ITS 

of the other two, is called the major term, and the sub- 
ject of the conclusion, which contains both the others, it 
called the minor term. 



JYote C, page 122. 

This is true in that arrangement of parts, which ren- 
ders the syllogism the most simple and the most perfect • 
though it will not hold in all those technical forms, in 
which it has been expressed. 

It may not be deemed wholly impertinent, in this place 
o give a brief description of that celebrated doctrine of 
modes and figures, in which simple syllogisms are involv- 
ed, in the ancient books of logick. By the mode of a 
syllogism was meant the designation of the quantity and 
quality of its propositions. By figure was meant the 
situation of the middle term with respect to the major 
and minor terms^ As the middle term occurs in each 
of the premises, it is susceptible of four different positions 
in relation to the extremes. Hence four figures have 
been invented. In the first the middle term is the sub- 
ject of the major proposition, and the predicate of the 
minor. In the second, it is the predicate, and in the 
third, the subject, of botli the premises. In the fourth it is 
the predicate of the major premise, and the subject of 
the minor. 

Each of the four figures had several modes, which were 
designated by the vowels A,E, I, O; characters, em- 
ployed by logicians to denote the quantity and quality 
of propositions. A, placed before a proposition, denot- 



176 NOTES. 

ed that it was a universal affirmative | E denoted uni- 
versal negative ; I, particular affirmative ; and O^ par- 
ticular negative. To assist the memory, the following 
couplet was contrived ; 

Asserit A, negat E, verum generaliter amba&. 
Asserit I, negat O, sed particulariter ambo. 

As all the possible combinations of three of these 
four letters, in three propositions, amount to sixty four, 
this number of modes might be formed. But of these, 
fifty three were excluded by certain established rules, 
and one rejected as useless ; leaving only ten, that were 
considered as legitimate. Several of these were repeat- 
ed in different figures, so as to make in the whole nine- 
teen conclusive modes. Each mode was furnished with 
an appropriate name, consisting of three syllables, and 
containing three of the vowels before named. The three 
syllables of the mode were placed before the propositions 
ot the syllogism, in order that the vowel letter, which 
alone was regarded, might indicate the quantity and 
quality of the proposition, before which it stood. 

To the first figure were given four modes ; which 
were denominated Barbara, Celarent, Darii, Ferio. The 
second figure had likewise four modes, namely, Cte- 
sare, Camestres, Festino, Baroco. The third had six 
modes, Darapti, Felapton, Disamis, Datisi, Bocardo, 
Ferison. The fourth had five modes, Bamarip, Cainenes, 
Dimatis, Festapo, Fresison. 



NOTES. ITT 

These barbarous wonls were thus formed into hexame- 
ter lines. 

Barbara, Celarent, Darii, Ferio quoque, prima?, 
Caesare, Camestres, Festitio, Baroco, secundse 
Tortia Darapti sibi vindicat atque Felapton ; 
Adjungens Disamis, Datisi, Bocardo, Ferison. 
Noil Bamaiip, Camenes, Dimatis, Festapo, Fresison. 

EXAMPLES. 

Figure First. 

Bar- Every animal has sensation ; 

Ba- Every man is an animal j 

lla. Therefore every man has sensation. 

Ce- No opinions, hurtful to the morals of society 

should be embraced ; 
La- Atheistical sentiments are hurtful to the morals 

of society 5 
Rent, Therefore atheistical sentiments should not be 

embraced. 

Da- All good men love peace 5 

Ri' Some statesmen are good men ; 

J. Therefore some statesmen love peace. 

Fe- No man of dissolute habits is a safe companion j 
Ri* Some men ot learning are dissolute in their 

habits ; 
0. Therefore some men of learning are not safe com- 
panions. 



178 NOTES. 

Figure Second. 

Ca- Every virtuous man is fit to be believed | 
MeS' No liar is fit to be believed ; 
TreS' Therefore no liar is a virtuous man, 

Ba- Every true patriot tries to promote the public 

good 5 
Eo' Some men in high stations do not try to promote 

the public good ; 
Co» Therefore some men in high stations are not true 

patriots. 

Figure Third. 

Du' All good christians vi^ili be saved 5 

Map* All good christians have sinned ; 

TL Therefore some, who have sinned, will be saved. 

Examples of the other modes may readily be formed. 

FINIS. 



i 



w 



<^ 



^ 



-^ 



^ 








v^ 



v> 





X 



Oo 



^ J o '^ 




o 




.^^ 




\> ^ ^ ^ /- "> O^ .- S ^ '^ " ' 

















«. .V 



t^^ 



' O. ■ 0^^ , c 



J> ,<. 



G^ 






^ <^ 



^ H ^ ^V 









x^^^ 




.5 ^'^c^ 



.^^i^^ll^ 



.0 o 



<' "-^ ^ H "^ Deacidified using the Bookkeeper process. 
'^ Neutralizing agent: Magnesium Oxide 
Treatment Date: Sept. 2004 






^■^f^ vV 






9 ; 



•^ ^^ 



'^> 




., ^ '°./. * , . ^ ,^ 



^ ^- 



V 



^'i/>. a)S 



PreservatioiiTechnologies 

-, A WORLD LEADER IN PAPER PRESERVATION 

S 111 Thomson Park Drive 

Cranberry Township, PA 16066 
(724) 779-21 1 1 



^nmiMiiiiuJ 






^ ■% 



„ \) n. \. 







^ 



o r> 



\ 



^ ^:^^ 



'(\i/A 



X 



Oo 





'^^ 



rO 



.\^^ 



cP- 



■^ 5' 



MHI 



>^. (^ 




-^. 1' -^S 



